EN： A relative clause (or adjective clause) uses a relative pronoun like 'who' to give more information about a noun. Here, 'who start using social media at a younger age' describes the noun 'children'.
中文： 关系从句（形容词从句）利用关系代词（如 who）来修饰前面的名词。在此句中，「who start using social media at a younger age」用来修饰主语名词「children」（孩子们）。
Students who study regularly usually get better grades.
定期复习功课的学生通常能获得更好的成绩。
EN： The modal verb 'may' expresses possibility, while 'perform worse' uses the comparative degree of 'badly' (worse) to indicate a lower level of performance compared to others.
中文： 情态助动词「may」表示「可能」，而「perform worse」则使用了副词 badly 的比较级（worse），用来表示与其他人相比表现得更差。
If you don't sleep well, you may perform worse on the exam tomorrow.
如果你没睡好，明天考试的表现可能会比较差。
EN： A noun clause introduced by 'that' is used as the direct object of a reporting verb (e.g., 'discover', 'find', 'say'). It contains a full subject and predicate.
中文： 由名词子句引导词「that」引导的名词子句，作为主要动词（如 discover、find、say）的直接受词，子句内部包含完整的主词与动词结构。
Scientists found that sleeping well improves memory.
科学家发现充足的睡眠能改善记忆力。
EN： A relative clause beginning with 'who' describes and gives more information about a person or group of people ('pupils').
中文： 由关系代名词「who」引导的关系子句（形容词子句），用来修饰并提供前方的先行词（人，在此为 pupils）更多细节资讯。
Students who read every day usually have higher test scores.
每天阅读的学生通常会有较高的测验分数。
EN： The passive voice structure 'be + past participle' (were compared) is used when the focus is on the action being done to the subject, rather than who performed the action. Here, 'compared with/to' means to examine two things to highlight their similarities or differences.
中文： 被动语态结构「be 动词 + 过去分词」（were compared）用于强调主语所遭受的动作，而非执行动作的主体。在此处，「compared with/to」表示将两者进行比较，以找出其异同之处。
The test results were compared with last year's data.
这次的测试结果与去年的数据进行了比较。
EN： The relative pronoun 'who' introduces a defining relative clause ('who waited until...') to specify or provide essential information about the antecedent pronoun 'those'.
中文： 关系代词「who」引导限定修饰的关系子句（who waited until...），用来明确指出或提供先行词代词「those」（那些人）的关键信息。
People who exercise regularly tend to live longer.
定期运动的人往往活得更久。
EN： In many countries, including European nations like Italy, 13 or 14 is a common age threshold defined by COPPA-like regulations or the GDPR, which require parental consent for users under 13 to 16 to open social media accounts.
中文： 在许多国家（包括意大利等欧洲国家），13 或 14 岁是法律规定的 重要年龄门槛。根据欧盟通用数据保护条例 (GDPR) 等法规，未满 13 至 16 岁的儿童开设社交媒体账号需要获得父母的同意。
EN： The phrase 'be equal to' functions as a predicate expression meaning to be identical or equivalent in amount, size, value, or effect to something else. Note that 'to' acts as a preposition here, so it is followed by a noun or noun phrase.
中文： 「be equal to」为表示「相当于…」或「与…相等」的固定句型。注意这里的「to」为介词，后方须接名词或名词短语（名词化结构）。
His income is equal to twice my salary.
他的收入相当于我薪水的两倍。
EN： A noun clause beginning with 'that' is used as the direct object of verbs like 'suggest', 'find', or 'show' to state a fact, result, or opinion.
中文： 由名词关联词「that」所引导的名词子句，常放在「suggest（表明）」、「find（发现）」或「show（显示）」等动词后面当作受词，用来说明事实、研究结果或观点。
Recent studies suggest that regular exercise improves sleep quality.
近期的研究表明，规律运动能改善睡眠品质。
EN： The passive voice is formed using 'be + past participle' (was carried out). It is used when the focus is on the action or the result rather than the person performing the action.
中文： 被动语态由「be 动词 + 过去分词」（was carried out）构成。当焦点放在动作本身或结果，而非执行动作的主体时，会使用被动语态。
The project was completed by the students on time.
这个专案是由学生们按时完成的。
EN： The phrasal verb 'carry out' means to conduct, perform, or execute a task, experiment, or research. In passive voice, it becomes 'be carried out by'.
中文： 片语动词「carry out」意思是执行、进行或完成一项任务、实验或研究。在被动语态中，会写作「be carried out by」（由……所进行）。
The survey was carried out by an independent company.
这项调查是由一家独立公司进行的。
EN： The preposition 'about' is used after the noun 'surveys' to indicate the topic or subject matter being investigated.
中文： 介词“about”（关于）常用于名词“surveys”（调查）之后，用来说明该调查所针对的主题或内容。
Researchers conducted a survey about the reading habits of teenagers.
研究人员针对青少年阅读习惯进行了一项调查。
EN： The phrase 'more than' is a prepositional phrase used before a number to mean 'over' or 'exceeding' that amount.
中文： 「more than」是一个短语，置于数字之前，意思是「超过」或「多于」该数量。
More than 100 people attended the lecture yesterday.
昨天有超过 100 人参加了这场讲座。
EN： The phrasal verb 'look at' means to examine, inspect, or consider something carefully. In research contexts, it often means to analyze data or results.
中文： 短语动词『look at』意为仔细检查、审视或考虑某事。在研究语境中，常表示『分析』数据或结果。
The committee will look at the new policy proposals next week.
委员会下周将审视新的政策提案。
EN： Parallel structure using the preposition 'in' to list multiple academic subjects: 'in maths, Italian, and English'. When listing items belonging to the same category, prepositions do not need to be repeated for each item.
中文： 平行结构（排比）：使用介词『in』来列举多个学科（in maths, Italian, and English）。当列举属于同一类别的项目时，介词不需要在每个项目面前重复使用。
She has high scores in history, science, and geography.
她在历史、科学和地理方面的分数很高。
EN： In British English, 'maths' is the standard abbreviation for mathematics, whereas American English uses 'math'. Additionally, 'Italian' in the Italian school system refers to the subject of native language and literature, similar to 'English' class in English-speaking countries.
中文： 在英式英语中，『maths』是数学（mathematics）的标准缩写，美式英语则使用『math』。此外，在意大利的教育体系中，『意大利语（Italian）』科目指母语与文学课，类似于英语国家学校里的『英语（English）』课。
EN： A gerund phrase (verb + -ing) can act as a singular noun and serve as the subject of a clause. It takes a singular verb (e.g., 'is').
中文： 动名词短语（动词 + -ing）可作为单数名词，在从句中担任主语，其后须搭配单数动词（如 is）。
Studying late at night makes me feel tired the next day.
熬夜读书会让我第二天感到疲倦。
EN： A relative clause introduced by the relative pronoun 'that' modifies a preceding noun ('distraction'). It acts as an adjective describing the noun.
中文： 由关系代词 that 引导的关系从句用来修饰前面的名词（distraction），扮演形容词的角色以提供更多细节。
Noise is a major problem that affects my concentration.
噪音是一个影响我专注力的主要问题。
EN： The conjunction 'that' introduces a noun clause functioning as the direct object of the verb 'explained'. Inside this clause, two predicate clauses ('is complex' and 'is connected...') are joined by the coordinating conjunction 'and'.
中文： 连词「that」引导一个名词从句，作为动词「explained」的直接宾语。在此从句内部，两个谓语（「is complex」与「is connected...」）由并列连词「and」连接。
She explained that the task was difficult and required extra time.
她解释说，这项任务很困难且需要额外时间。
EN： The prepositions 'to' is followed by a nominal clause (noun clause) starting with 'how', which functions as the object of the preposition. The passive voice 'are built' describes how the platforms were created/designed.
中文： 介词「to」后面接由「how」引导的名词从句，作为介词的宾语。被动语态「are built」描述社交平台是如何被构建或设计的。
Our success depends on how team members are supported.
我们的成功取决于团队成员如何获得支持。
EN： Indirect speech (reported speech) is used to report what someone else said. When the main reporting verb (e.g., 'said') is in the past tense, the verbs in the noun clause usually shift to a past tense, though present tense can be kept if reporting a timeless fact.
中文： 间接引语（转述语气）用于转述他人说过的话。当主句的转述动词（如 'said'）为过去式时，名词从句中的动词通常会改用过去式，但若转述的是普遍事实或现状，有时也会保留现在式。
She said that the report was completed yesterday.
她说这份报告昨天已经完成了。
EN： Nested noun clauses with 'that' (which can be omitted). Here, 'said that...' contains a second embedded noun clause 'shows (that) social media is...' acting as the object of 'shows'.
中文： 嵌套名词从句（Nested Noun Clause）：本句中，主句动词 'said' 后接了一个由 'that' 引导的名词从句，而该从句内部的动词 'shows' 后面又省略了连接词 'that'，引导另一个名词从句作为 'shows' 的宾语。
He believes that the study proves online learning is effective.
他相信这项研究证明了在线学习是有效的。
EN： The structure 'be to blame (for something)' is an active infinitive used with a passive meaning, indicating that someone or something is responsible for a bad outcome or mistake.
中文： 结构「be to blame (for something)」虽然使用主动不定式，但具有被动意思，用来表示某人或某事应对不良结果或错误「负责」或「是……的起因」。
Bad weather was largely to blame for the delay of the train.
恶劣的天气是导致火车误点的主因。
EN： A noun clause acting as a direct object introduced by the conjunction 'that'. The clause 'that social media is directly to blame...' complements the transitive verb 'prove'.
中文： 由连接词「that」引导的名词子句作为宾语。子句「that social media is directly to blame...」补充说明及物动词「prove」的内容。
The scientists proved that the new treatment is safe.
科学家们证明了这种新疗法是安全的。
EN： The phrasal verb 'take account of' (or 'take into account') means to consider or remember something when assessing a situation.
中文： 片语动词『take account of』（或 take into account）意思是『考虑到』或『将……纳入考量』，常用于评估或分析情况时。
We must take account of the bad weather before planning the outdoor event.
在规划户外活动之前，我们必须考虑到恶劣的天气。
EN： The preposition 'including' is used to introduce examples that belong to a larger group or category mentioned earlier.
中文： 介系词『including』（包括）用于引导属于前面所提及之更大群组或范畴的具体例子。
The fee covers all activities, including the guided tour and lunch.
费用包含所有活动，包括导览和午餐。
EN： The past perfect tense ('had opened') is used to express an action that happened before another past action ('were tested' / 'scored').
中文： 过去完成式（had + 过去分词）用于表示在过去某个特定时间点或动作（如 'were tested' 或 'scored'）之前就已经发生的动作。
She had finished her homework before her friends arrived.
在她的朋友到达之前，她就已经完成作业了。
EN： Relative clauses starting with 'who' are used to give more information about a person or group of people ('those who...').
中文： 关系代词 'who' 用于引导关系从句，修饰前面的先行词（在此处为 'those'，指代「那些人」），以提供更多关于该人群的信息。
Students who study regularly usually get good grades.
定期复习的学生通常会取得好成绩。
EN： The linking verb 'remain' can be followed by a subject complement (an adjective like 'the same') to indicate that a state or condition continues without changing.
中文： 连系动词「remain」（保持）后面可接主语补语（如形容词「the same」），用来表示某种状态或情况持续保持不变。
Despite the harsh winter, the room temperature remained warm.
尽管冬天很严寒，室温依然保持温暖。
EN： The preposition 'at' is used before a specific age or age range to show the time when something happens or applies.
中文： 介词「at」可用于特定的年龄或年龄层之前，表示某事发生的时间点或适用年龄。
She learned to play the piano at age 6.
她在6岁时学会了弹钢琴。
EN： The degree modifier 'even' is used before comparative adjectives (like 'wider') to emphasize a greater degree or contrast.
中文： 程度修饰词「even」（甚至、更加）常用于比较级形容词（如「wider」）之前，用来强调程度的加深或强烈的对比。
His second test score was even higher than his first.
他第二次考试的成绩甚至比第一次更高。
EN： The linking verb 'became' (past tense of 'become') connects the subject 'the gap' to the subject complement 'wider', describing a change in state.
中文： 连系动词「became」（become 的过去式）用来连接主语「the gap」与主语补语「wider」，用以描述状态的改变。
The weather became colder after the rain.
下雨过后，天气变得更冷了。
EN： The Present Perfect Tense (have/has + past participle) is used here to describe an action that occurred at an unspecified time in the past and has direct relevance or effect on the present situation.
中文： 现在完成时（have/has + 过去分词）在此用于描述过去某个未明确说明时间发生的动作，且该动作对现在的情况有直接的影响或相关性。
Recent surveys have shown a growing interest in online learning.
最近的调查显示人们对在线学习的兴趣日益浓厚。
EN： The preposition 'about' is followed by a gerund clause ('children joining social media...'), where 'children' acts as the logical subject of the gerund 'joining'. This structure explains the specific content or topic of the 'concerns'.
中文： 介词 'about' 后面接动名词短语（'children joining social media...'），其中 'children' 作为动名词 'joining' 的逻辑主语。这种结构用来说明「担忧」（concerns）的具体内容或主题。
There are many concerns about teenagers spending too much time on video games.
许多人对青少年花太多时间玩电子游戏表示担忧。
重要单词附有 IPA 发音、定义、例句和互动式测验。
在本文中： 学生；尤指小学生
在本文中： 账户；用于使用在线服务的用户资料
在本文中： 分散注意力的事物；使你无法专注于正在做的事情的东西
在本文中： 标准化的；以相同方式对所有学生进行，以便比较结果
在本文中： 怀疑；认为某事可能是真的但不确定
在本文中： 分析；仔细研究以理解
在本文中： 表现；某人做某事的水平
在本文中： 复杂的；由许多相互关联的部分组成；不简单
片语包含类型标示、双语定义、用法说明和例句。
To perform or conduct a task, research, or experiment.
执行；进行
To consider or include something when judging a situation.
考虑到；将……计算在内
A test that is administered and scored in a consistent, or standard, manner.
标准化测验；统一考试
The regular pattern or behavior of using social media platforms.
社交媒体使用习惯