句型9
It was + 时间段+before…."过了多久才(怎么样)……"
It was not long before…."不久，就……"
It will (not) be +时间段+before…."要过多久(不久)……才……"(before从句谓语动词要用一般时态)
[例句]
It was not long before he sensed the danger of the position.不久他就意识到他处境的危险。
It was five days before he came back. 五天后他才回来。
It will be half a year before you graduate from the school. 再过半年你才能毕业。
It will not be long before they understand each other. 他们大概不久就会互相了解。
句型10
in case of…(+n.) "以防;万一";
in case that…"以防，万一……"(谓语动词用一般现在时态或should+动词原形)
[例句]
In case of fire, what should we do?
Please remind me about it in case I forget/should forget. 万一我忘了，请提醒我。
In case (that) John comes/should come, please tell him to wait.
Please take your umbrella in case (that it rains/should rain).带上雨伞，以防下雨。
句型11
It强调句型
强调句的基本构成：It is/was + 被强调的部分 + who(主要指人时)/that + 其余部分
[注意1]
这种结构可以强调句子的主语、宾语、状语(包括时间，地点，方式，原因等)，但是不能强调谓语动词(参考句型15)。
原句的谓语动词如果是现在或将来时态，用It is…that/who….;
原句的谓语动词如果是过去时态，用It was…that/who….;
强调时间、地点、原因或方式时不要用when, where或how, 必须用that。
[例句1]
I saw him in the street yesterday afternoon.
→It was I who saw him in the street yesterday afternoon.(强调主语)
→It was in the street that I saw him yesterday afternoon.(强调地点状语)
→It was yesterday afternoon that I saw him in the street.(强调时间状语)
→It was him that/who I saw in the street yesterday afternoon.(强调宾语)
[例句2]
He didn't go to bed until his mother came back.
→It was not until his mother came back that he went to bed.
He didn't do his homework until his father came back from work.
→It wasn't until his father came back from work that he did his homework.
[例句3]
Only when you nearly lose someone do you fully realize how much you value him.
→It is only when you nearly lose someone that you fully realize how much you value him.
只有你快要失去某个人时，你才意识到你是多么尊重他。
[例句4]
I was late again because the traffic was very heavy during the rush hour.
→It was because the traffic was very heavy during the rush hour that I was late again.
(强调句中只能强调由because引导的原因状语从句，because不能换成since, as, for, now that等)
[注意2]强调句的疑问结构
一般疑问句 Is / Was it +被强调部分 +who / that …?
特殊疑问句 特殊疑问词+is /was +it +who / that…?
What is/was it that…? Who is/was it that…? When is/was it that…?
Where is/was it that…? Why is/was it that…? How is/was it that…?
[例句1]
I saw him in the street yesterday afternoon.
→When was it that you saw him in the street?
→Who was it that you saw in the street yesterday afternoon?
→Where was it that you saw him yesterday afternoon?
[例句2]
I don't know when he will come back.
→I don't know when it is that he will come back.(宾语从句疑问词后用陈述句语序)
-How was it that you got in touch with Mr. Smith? 你是怎么和Smith先生联系上的?
-Trough a friend of mine. 通过一个朋友。
