it is sb doing与there is sb doing的区别

It's noisy; I think it must be some dogs barking.
我记得固定搭配是 there be sb / sth doing sth。但没见过 it be sb doing 呀！请老师讲解一些 it 做主语的用法吧！谢谢！

▲It is sb / sth doing sth 和 There is sb / sth doing sth 都可以说，但意思不同：

1. It is sb / sth doing sth 的意思是“某人或某物正在做某事”。如：

A: There is a terrible smell. 有股难闻的气味。

B: Oh, it must be the cake burning. 一定是糕点烤焦了。

Listen, it’s the bell ringing. Let’s hurry. 听，是铃声在响了，我们赶快吧。

2. There is sb / sth doing sth 的意思是“有某人或某物正在做某事”。如：

There’s a dog lying on the floor. 地上躺着一条狗。

There’s a car waiting at the door. 门口有一辆车等着。

There was a girl sitting by his side. 有一个姑娘坐在他旁边。

There were some children swimming in the river. 有些小孩在河里游泳。

There werecrowds of people waiting to get in. 有许许多多的人在等着进去。

There was water dripping from ahole in the ceiling. 水从天花板的窟窿中滴下来。

▲你的句子，根据句首的 It's noisy 可知，后面用 It is sth doing sth 意思才通顺：

It's noisy; I think it must be some dogs barking. 好吵啊，我想一定狗在叫吧。

波波老师 -

擅长：英语考试 | 采纳率 54% | 回答于 2014-11-17 23:17

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