long do you think it will be______the computer company puts forward a new product?How long do you think it will be______the computer company puts forward a new product?A.before B.since C.until D.that 请问这道题的答案为什么是A而不是C呢

long do you think it will be______the computer company puts forward a new product?How long do you think it will be______the computer company puts forward a new product?A.before B.since C.until D.that 请问这道题的答案为什么是A而不是C呢
long do you think it will be______the computer company puts forward a new product?
How long do you think it will be______the computer company puts forward a new product?
A.before B.since C.until D.that
请问这道题的答案为什么是A而不是C呢?

long do you think it will be______the computer company puts forward a new product?How long do you think it will be______the computer company puts forward a new product?A.before B.since C.until D.that 请问这道题的答案为什么是A而不是C呢
A 这是个固定的时间状语从句 it will be + 一段时间+ before sth.happens

it will be +time +before 意思为“多久才”如：
it will be three years before we graduate
三年以后我们才毕业。
it will be lo9ng before we arrive home.
好久才能到家。

列情况下宜用before不用until.
1.主句为肯定式，谓语为终止性动词时只用before.
For example:
1). He fell asleep before I could take off his clothes.
2). We arrived there before it started to rain.
3). The holida...

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列情况下宜用before不用until.
1.主句为肯定式，谓语为终止性动词时只用before.
For example:
1). He fell asleep before I could take off his clothes.
2). We arrived there before it started to rain.
3). The holiday came to an end before I knew it.
4). He almost knocked me down before he saw me.
2.主句谓语动词强调动作的迟缓性，只用before,这时常伴有时间段状语或时间段暗示。
For example:
It was quite a long time before he found the elephant.过了很长时间，他才找到大象。
We had walked a long way before we found some water.走了很长的路我们才找到水。
We had sailed for two days before we saw the land.航行了两天我们才发现陆地。
It was midnight before my brother came home.我哥哥直到半夜才回来。
3.如果强调从句谓语动作未发生就发生主句谓语动作，只用before,这时常译为“未及（不等）……就……”
For example:
1）We can leave early in the morning before it gets too hot.趁天还不太热，我们上午早点离开。
2）I must write it down before I forget it.趁我还未忘，我必须把它记下来。
4.表示“与其说……倒不如……”,“与其……毋宁……”的意思时只用before.
For example:
I would give up my job before I agree to be dismissed.我与其被解雇还不如先辞职。
He will die of hunger before he steals.他宁愿饿死也不愿意去偷。
5．在某些特定句型中用before。
It was (not) long before…（不久）过了很长时间才…
It will (not) be long before…（不到）要过很长时间才会…
For example:
.It will probably not be long before they understand each other.
他们大概过不久就会互相了解。
It was not long before the whole country rose up.
不久全国人民奋起反抗。
三.下列情况一般使用until
1。主句是持续性谓语动词时，肯定,否定都可以，但意义完全不同，肯定表示动作终止，而否定表示动作开始。
For example:
1). We discussed the problem until/before he came back.
我们一直讨论到他回来。
2). We didn’t discuss the problem until he came back.
我们一直等到他回来才讨论问题。
2．Not…until…句型尽管在某些情况下可与before互换使用，但在强调句中一般仍用until;
1). It was not until he told me that I knew it.直到他告诉我我才知道这件事。
2）.It was not until he finished his homework that he went home.直到完成作业他才回家。
3）放于句首时用until.
For example:
Antil he finished his homework ，he didn’t go home. 直到完成作业他才回家。
应注意：在使用not until时，若not until放于句首，句子应部分倒装。 For example:
Not until he finished his homework，did he go home. 直到完成作业他才回家

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选A

A

C until 可以表示某个时间点之前的时间，从现在起呆电脑公司推出新产品还有多久

A，这里的before的意思为“要多久。。。才。。。”
如果选C，前面要有个not,即not...until才是正确的搭配

It will be long before he comes back.
再过很久他才回来

A