EN： Present Perfect Passive Voice (have/has been + past participle) is used to describe an action that has been completed at an unspecified time in the past, focusing on the result or the receiver of the action rather than who performed it.
中文： 现在完成时的被动语态（have/has been + 过去分词）用于描述在过去不特定时间点已完成的动作，其焦点在于动作的承受者或结果，而非动作的执行者。
Many new stars have been discovered by this telescope.
这架望远镜已经发现了许多新恒星。
EN： The phrase 'for the first time in history' is a prepositional phrase used as an adverbial modifier to emphasize that an event has never occurred before in human records.
中文： 短语「for the first time in history」（历史上第一次）是用作副词修饰语的介词短语，用以强调某个事件在人类记载中从未发生过。
The two countries signed a peace treaty for the first time in history.
这两个国家在历史上首次签署了和平条约。
EN： Non-defining relative clauses (using 'which') add extra, non-essential information about a noun. They are separated from the main clause by a comma, and 'which' cannot be replaced by 'that'.
中文： 非限定关系从句（使用 'which'）用于对先行词（名词）进行补充说明，提供非必要的额外信息。这类从句前通常有逗号隔开，且其中的关系代词 'which' 不能用 'that' 代替。
He bought a new laptop, which cost him a fortune.
他买了一台新笔记本电脑，花了他一大笔钱。
EN： The past simple tense is used to describe completed actions that occurred at a specific time in the past (e.g., 'announced', 'happened').
中文： 一般过去时用于描述在过去特定时间已经完成的动作或状态（例如句中的 'announced' 和 'happened'）。
The company launched its first satellite last year.
该公司去年发射了其第一颗卫星。
EN： The term 'commercial spaceflight' refers to the growing private space industry (such as SpaceX or Axiom Space), which represents a shift from government-funded space exploration (like NASA) to private-sector initiatives, enabling more diverse scientific research in orbit.
中文： 「商业太空飞行」（commercial spaceflight）指的是蓬勃发展的民营太空产业（如 SpaceX 或 Axiom Space）。这代表了太空探索从政府资助（如美国国家航空航天局 NASA）向私营部门主导的转变，从而使更多元化的科学研究得以在轨道上进行。
EN： Noun Clause as Object (that-clause): The verb 'believe' is followed by a noun clause functioning as its direct object. The conjunction 'that' is omitted here, which is very common in informal and semi-formal English when the meaning is clear.
中文： 名词从句作为宾语（that 从句）：动词「believe」（相信）后面接一个名词从句作为其直接宾语。在这里省略了连接词「that」，这在非正式和半正式的英文中非常常见，只要语义清楚即可省略。
They believe the project will succeed.
他们相信这个企划会成功。
EN： Simple Present Tense for General Truths or Current Beliefs: The verbs 'believe' and 'marks' are in the simple present tense because they express a current, ongoing belief and a general statement about the significance of the achievement.
中文： 一般现在时表示普遍真理或当前信念：动词「believe」和「marks」使用一般现在时，因为它们表达了当前持续的信念，以及对成就重要性的客观陈述。
She believes this technology improves our daily lives.
她相信这项技术改善了我们的日常生活。
EN： The Present/Past Perfect or Simple Past with 'for' + duration. Here, 'was' (Simple Past) is used because the situation of ultrasound being the *only* method has just ended with the new X-ray breakthrough. 'For more than forty years' indicates the duration of this past state.
中文： 使用「for」加上一段时间来表示持续的状态。在这里使用过去简单式「was」，是因为随着新 X 光技术的突破，超声波作为「唯一」方法的状态已经结束。「For more than forty years」指出这个过去状态持续的时间。
For more than ten years, this old computer was the only tool I had for my work.
十多年来，这台旧电脑是我工作上唯一拥有的工具。
EN： Relative clauses with 'that'. The relative pronoun 'that' introduces a defining relative clause ('that doctors could use in space') to modify the noun phrase 'the only imaging method'. Since 'that' acts as the direct object of the verb 'use', it could grammatically be omitted, but keeping it adds clarity.
中文： 使用「that」引导的关系从句。关系代词「that」在此引导一个限定修饰的关系从句（that doctors could use in space），用来修饰名词短语「the only imaging method」（唯一的成像方法）。因为「that」在从句中担任动词「use」的直接宾语，在语法上是可以省略的，但保留它能使语义更清晰。
This is the only book that the students must read this semester.
这是学生们本学期唯一必须阅读的书。
EN： The subordinating conjunction 'because' is used to introduce a dependent clause (adverbial clause of reason) that explains the cause or reason for the action or state in the main clause.
中文： 从属连词“because”（因为）用于引导从属子句（原因副词子句），用来解释主句中动作或状态的原因。
She stayed at home because it was raining heavily.
她待在家里，因为雨下得很大。
EN： The simple present tense is used here to state general facts or permanent situations. In the third-person singular ('it'), the verb 'require' takes the ending '-s' to become 'requires'.
中文： 这里使用现在简单式来陈述普遍事实或永久的情况。在第三人称单数（it）之后，动词“require”字尾需加“-s”变为“requires”。
This recipe requires fresh ingredients.
这道食谱需要新鲜的食材。
EN： The conjunction 'as' is used here to describe two developments that are happening at the same time, meaning 'while' or 'in proportion to the way in which'. It often connects a changing situation with its consequence.
中文： 连接词「as」在此处用于描述同时发生的两个发展，意思是「随着」或「与…同时」。它通常将一个正在变化的情况与其产生的结果联系起来。
As the weather gets colder, people spend more time indoors.
随着天气变冷，人们待在室内的时间也变多了。
EN： The passive voice 'are needed' (be verb + past participle) is used when the agent performing the action (the people who need the tools) is obvious, unimportant, or unknown, focusing the attention on the receiver of the action ('better medical tools').
中文： 被动语态「are needed」（be 动词 + 过去分词）用于执行动作的人（需要工具的人）是显而易见、不重要或未知的情况，借此将注意力集中在接受动作的客体（「更好的医疗工具」）上。
More volunteers are needed for the upcoming charity event.
即将举办的慈善活动需要更多的志愿者。
EN： Apposition (Appositive Phrase): An appositive is a noun or noun phrase that sits next to another noun to rename or describe it. In this sentence, 'the lead researcher from Mayo Clinic in Minnesota' is an appositive phrase that provides more information about the subject 'Doctor Sheyna Gifford'. It is set off by commas.
中文： 同位语（同位语短语）：同位语是紧跟在另一个名词旁边，用来重新命名或描述该名词的名词或名词短语。在本句中，「the lead researcher from Mayo Clinic in Minnesota」（来自明尼苏达州妙佑医疗国际的首席研究员）是一个同位语短语，用来提供关于主词「Doctor Sheyna Gifford」（谢娜·吉福德医生）的更多资讯，前后以逗号隔开。
Mr. Davis, the principal of our school, gave a speech.
戴维斯先生，也就是我们学校的校长，发表了演讲。
EN： Prepositional Phrases as Modifiers: Prepositional phrases starting with 'from' and 'in' can act as adjectives to describe nouns. Here, 'from Mayo Clinic' describes 'the lead researcher', and 'in Minnesota' describes 'Mayo Clinic', creating a chain of specific details.
中文： 介系词短语作为修饰语：以「from」和「in」开头的介系词短语可以充当形容词来修饰名词。在这里，「from Mayo Clinic」修饰「the lead researcher」，而「in Minnesota」修饰「Mayo Clinic」，形成了一连串具体细节的修饰。
The teacher from the local college in Taipei won an award.
来自台北当地大学的那位老师获奖了。
EN： Mayo Clinic is a highly prestigious, non-profit academic medical center based in Rochester, Minnesota. It is consistently ranked among the best hospitals in the United States and the world, known for its integrated clinical practice, education, and research.
中文： 妙佑医疗国际（Mayo Clinic）是总部位于明尼苏达州罗彻斯特的一所享有盛誉的非营利学术医疗中心。它在全球最佳医院排名中一直名列前茅，以其整合性的临床实践、医学教育和科学研究而闻名。
EN： Noun clauses introduced by 'that' function as the direct object of a reporting verb (like 'said'). The conjunction 'that' is often omitted in informal speech, but it is kept here to clearly introduce the reported statement.
中文： 由「that」引导的名词子句在此作为述说动词（如「said」）的直接宾语。在口语中「that」常被省略，但在此处保留以清晰地引出所转述的内容。
He said that the new project would start next week.
他说新项目将于下周开始。
EN： The quantifier 'too much' is used with uncountable nouns (like 'radiation') to express an excessive amount that goes beyond what is desirable or safe.
中文： 数量词「too much」与不可数名词（如「radiation」）连用，用以表示超过理想或安全范围的过多数量。
Drinking too much coffee can make you feel nervous.
喝太多咖啡会让你感到紧张。
EN： The coordinating conjunction 'so' is used to connect two independent clauses, showing a cause-and-effect relationship where the second clause is the result of the first.
中文： 等立连接词「so」（因此/所以）用于连接两个独立子句，表示因果关系，第二个子句为第一个子句所产生的结果。
The weather was terrible, so we decided to stay indoors.
天气非常糟糕，所以我们决定待在室内。
EN： The 'that-clause' acts as a noun clause serving as the direct object of the verb 'believed'. It contains a gerund phrase 'taking clear X-ray images in orbit' acting as the subject of the noun clause.
中文： 由「that」引导的子句作为名词子句，担任动词「believed」的直接受词。该子句内部包含一个动名词片语「taking clear X-ray images in orbit」作为该子句的主词。
She believed that learning a new language was very rewarding.
她认为学习一门新语言是非常值得的。
EN： The verb 'give' is a ditransitive verb, which means it can take two objects: an indirect object (the recipient, 'Doctor Gifford's team') and a direct object (the thing being given, 'a new opportunity'). The structure is: Subject + give + Indirect Object + Direct Object.
中文： 动词「give」（给予）是一个双宾语动词（ditransitive verb），这意味着它可以接两个宾语：间接宾语（接受者，即「吉福德医生的团队」）和直接宾语（被给予的事物，即「一个新的契机」）。其结构为：主词 + give + 间接宾语 + 直接宾语。
The company gave the employees a special bonus.
这间公司给了员工们一份特别的奖金。
EN： Noun adjuncts (or noun premodifiers) occur when a noun functions as an adjective to modify another noun. In 'X-ray machines', 'X-ray' acts as an adjective describing the type of 'machines'. Similarly, in 'spaceflight', 'space' modifies 'flight'.
中文： 名词修饰语（noun adjuncts）是指名词当作形容词来修饰另一个名词。在「X-ray machines」中，「X-ray」（X 光）作为形容词来描述「machines」（机器）的类型。同样地，在「spaceflight」中，「space」（太空）修饰了「flight」（飞行）。
She bought a new leather jacket at the clothing store.
她在服装店买了一件新的皮革夹克。
EN： The prepositional phrase 'with...' is used as an adjective phrase to modify the noun 'flight crew'. It describes a characteristic or possession of the noun, meaning 'having' or 'possessing'.
中文： 介词短语「with...」在此作为形容词短语，用来修饰名词「flight crew」（机组人员）。它描述了该名词的特征或拥有的事物，意思是「具有」或「拥有」。
A teacher with extensive experience joined our school.
一位拥有丰富经验的老师加入了我们学校。
EN： The Simple Past Tense ('carried') is used to describe a completed action that took place at a specific time in the past (indicated here by the time marker 'In 2022').
中文： 简单过去式（「carried」）用于描述在过去特定时间（此处由时间标记「In 2022」指出）已经完成的动作。
In 2019, the company launched its first smartphone.
在 2019 年，这家公司推出了它的第一款智能手机。
EN： The phrase 'be able to' is used to express ability or capability, often in a specific past situation where someone succeeded in doing something. It is followed by the base form of the verb.
中文： 「be able to」短语用于表示能力或能够做到某事，通常指在过去特定情况下成功完成了某事。其后接动词原形。
She was able to finish the project on time despite the difficulties.
尽管面临种种困难，她还是能够按时完成专案。
EN： The relative pronoun 'which' can be used to introduce a non-defining relative clause that refers back to the entire preceding clause, rather than just a single noun. It is always preceded by a comma.
中文： 关系代词「which」可用于引导非限定关系从句，用来修饰前面整个从句的内容，而不仅仅是单个名词。在此用法中，which 前面必须加上逗号。
He passed the difficult exam, which surprised everyone.
他通过了那场艰难的考试，这让每个人都感到很惊讶。
EN： The conjunction 'that' is used to introduce a noun clause functioning as the direct object of the reporting verb 'said'. In informal English, 'that' is often omitted, but it is retained here for clarity and formal structure.
中文： 连接词「that」用于引导名词子句，作为转述动词「said」（说）的直接受词。在非正式英语中，「that」常被省略，但在此处保留以使结构更清晰和正式。
She said that the results would be ready tomorrow.
她说结果明天就会出来。
EN： The preposition 'for' is followed by a gerund ('diagnosing') to express the purpose or function of an object or action. A gerund is a verb ending in -ing that functions as a noun.
中文： 介词「for」后面接动名词（在此为「diagnosing」），用来表示某物或某行为的目的或功能。动名词是动词字尾加 -ing 并具有名词功能的词。
This tool is excellent for measuring small distances.
这个工具非常适合用来测量微小的距离。
重要单词附有 IPA 发音、定义、例句和互动式测验。
在本文中： 突破，重大进展
在本文中： 商业的，营利性的
在本文中： 超声波（检查）
在本文中： 限制，局限性
在本文中： 传统的
在本文中： 辐射
在本文中： 手提式的，便携的
在本文中： 极小的，最小限度的
在本文中： 诊断（疾病、问题）
片语包含类型标示、双语定义、用法说明和例句。
A journey through space
太空飞行，航天
A technique used to create images of the human body for clinical purposes
医学成像技术
The substance or material through which a sound wave travels
声波介质
The personnel who operate an aircraft or spacecraft during flight
机组人员，乘务组