★　Which of these do you think is the mostuseful invention?

　　Which of these do you think is the most useful invention?你认为哪一种是最有用的发明。

　　Do you think 语法上通常认为是插入语，意思是说，去掉它们以后，句子仍然成立。（如果认为you 是主语，think 是谓语，其它成份是宾语从句也有道理）。例如：

　　Who do you think is over there?

　　你认为谁在那儿呢？

　　What do you think has happened?

　　你认为发生了什么事情了？

　　★　He was always trying out new ideas.

　　He was always trying out new ideas.他总是在试验一些新的想法。

　　Be always doing 表示总是在做着表达说话人的一种感情，如赞扬或者批评。例如：

　　My students are always studying hard.

　　我的学生总是在努力学习。

　　He is always making some mistakes.

　　他总是在犯一些错误。

　　★　His father saw him sitting on some eggs.

　　His father saw him sitting on some eggs.他父亲看到他正坐在一些鸡蛋上。

　　See sb.doing 表示看见某人正干某事。同义词组see sb.do 则表示看见某人做了某事。类似see 的动词还有hear,feel,watch.例如：

　　I saw him get on the bus.

　　我看见他上了车了。

　　I saw a girl reading in the park.

　　我看见一个女孩在公园里读书。

　　I heard someone singing in the classroom.

　　我听到有人在教室里唱歌。

　　★　The teacher could not answer all of them.

　　The teacher could not answer all of them.老师不可能回答所有的问题。

　　句中否定词not 和all在一起，构成不完全否定。例如：

　　All the students are not here.

　　所有的学生没都来。

　　I didnt take all of them.

　　我没全拿走。

　　★　So he wanted to send Tom away from school.

　　So he wanted to send Tom away from school.所以他想让汤姆离开学校。

　　To send 是一动词不定式。作want 的宾语。动词不定式是原形动词前加一to.动词不定式在句中可作宾语或宾语补足语等。例如：

　　I want to buy some books.

　　我想买几本书。

　　He came here to help me.

　　他来帮助我。

　　I asked him to turn it down.

　　我让他把收音机关小。

　　★　She sent for a doctor.

　　She sent for a doctor.她派人去请大夫。Sent for 表示派人把某人请来。

　　Sent 是send 的过去式。Send 表示派遣。例如：

　　Her classmate was ill and she sent for the doctor.

　　她的同学病了，所以她派人请了大夫。

　　Who sent you here?

　　谁派你来的？

　　★　Which of these do you think is the mostuseful invention?

　　Which of these do you think is the most useful invention?你认为哪一种是最有用的发明。

　　Do you think 语法上通常认为是插入语，意思是说，去掉它们以后，句子仍然成立。（如果认为you 是主语，think 是谓语，其它成份是宾语从句也有道理）。例如：

　　Who do you think is over there?

　　你认为谁在那儿呢？

　　What do you think has happened?

　　你认为发生了什么事情了？

　　★　He was always trying out new ideas.

　　He was always trying out new ideas.他总是在试验一些新的想法。

　　Be always doing 表示总是在做着表达说话人的一种感情，如赞扬或者批评。例如：

　　My students are always studying hard.

　　我的学生总是在努力学习。

　　He is always making some mistakes.

　　他总是在犯一些错误。

　　★　His father saw him sitting on some eggs.

　　His father saw him sitting on some eggs.他父亲看到他正坐在一些鸡蛋上。

　　See sb.doing 表示看见某人正干某事。同义词组see sb.do 则表示看见某人做了某事。类似see 的动词还有hear,feel,watch.例如：

　　I saw him get on the bus.

　　我看见他上了车了。

　　I saw a girl reading in the park.

　　我看见一个女孩在公园里读书。

　　I heard someone singing in the classroom.

　　我听到有人在教室里唱歌。

　　★　The teacher could not answer all of them.

　　The teacher could not answer all of them.老师不可能回答所有的问题。

　　句中否定词not 和all在一起，构成不完全否定。例如：

　　All the students are not here.

　　所有的学生没都来。

　　I didnt take all of them.

　　我没全拿走。

　　★　So he wanted to send Tom away from school.

　　So he wanted to send Tom away from school.所以他想让汤姆离开学校。

　　To send 是一动词不定式。作want 的宾语。动词不定式是原形动词前加一to.动词不定式在句中可作宾语或宾语补足语等。例如：

　　I want to buy some books.

　　我想买几本书。

　　He came here to help me.

　　他来帮助我。

　　I asked him to turn it down.

　　我让他把收音机关小。

　　★　She sent for a doctor.

　　She sent for a doctor.她派人去请大夫。Sent for 表示派人把某人请来。

　　Sent 是send 的过去式。Send 表示派遣。例如：

　　Her classmate was ill and she sent for the doctor.

　　她的同学病了，所以她派人请了大夫。

　　Who sent you here?

　　谁派你来的？