it is

it is defined as 意为：被定义为...defined 英[dɪ'faɪnd] 美[dɪ'faɪnd]adj. 有定义的，明确的; 清晰的，轮廓分明的;v. 给…下定义，解释，限定(define的过去式和过去分词);A clearly defined track now leads down to the valley 眼前有一条清晰可辨...

not...until直到...才...1.用when 表示时间,比如 It is not until 4 years old when he could talk.他直到4岁才会说话.2.that后边跟一个句子,it就指的是整个句子 见到了后你把that从句跟it替换,意思就很明显了

It’s surprising that… (should)………竟然……It’s a pity/shame that…(should)………竟然…（3）It verb sb. + clause= It is v-ing + clause It+surprise/delight/interest/disappoint/worry/disturb/annoy/amaze/bother/concern/frighten/please/anger sb. that…（4）It verb (to sb...

It's easy for him to solve puzzles.（对他来说解决谜题很容易。）It's natural for children to learn languages at a young age.（对儿童来说在年幼时学习语言是自然的。）4.表达观点或感受：使用形容词来描述某人对特定行为或事物的观点或感受。例如：It's exciting for us to explore new ...

It's time for 和It's time to 都是提醒别人做某事的句型，意思是该做某事了，做某事的时间到了。1、It's time for +名词、名词短语、动名词（动词ing形式）eg：It's time for bed.该睡觉了。2、It's time for +动词、动词短语，It's time to do sth.eg：It's time to go to bed...

这是例行的手续。4、It is a matter of fact that excessive exposure to the sun's rays, especially in fairskinned people, can cause skin cancer.事实上，过度地暴露于阳光之下，特别是对那些白皮肤的人们来说，易患皮肤癌。5、But also, in part, it is a matter of tradition and ...

据说他的孩子不见了。收藏指正 4.It is said that she is a siren.据说她是个妖艳女人。收藏指正 5.It is said that the universe is infinite.据说宇宙是无限的。收藏指正 6.It is said that he is a millionaire.据说他是一个百万富翁。收藏指正 7.It is said that the country is in ...

以上两句中的it是形式主语,真正的主语是后面的不定式短语。3) It is considered no good reciting without understanding. 不理解的背诵被认为是没有好处的。4) It is no use crying over spilt milk. 覆水难收。以上两句中的it是形式主语,真正的主语是V-ing形式。5) It is a fact that English is being ...

It is believed that 意思是：有人相信；据信；人们认为；大家相信；人们相信 例句：1、It is believed that he has told the truth.人们相信他说了实话。2、It is believed that it is a worthwhile task.人们认为这是一项值得做的工作。3、It is believed that the troops have already crossed...

I have been here since 1989.2) since +一段时间+ ago I have been here since five months ago.3) since +从句 Great changes have taken place since you left.Considerable time has elapsed since we have been here.4) It is +一段时间+ since从句 It is two years since I became ...