21.

You should drive at a safe speed.

你应该以安全的速度行驶。

22.

I have a dog. She has a cat.

我有一只狗。她有一只猫。

23.

Which bus goes to Central Park?

哪路巴士到中央公园?

24.

There are a lot of fish in the pond.

池塘里有很多鱼。

25.

It may take a little longer than I expected.

可能要比我预计的时间长一点。

26.

Were you playing with Tom at his house?

你和汤姆在他家玩吗？

27.

Let's begin.

我们开始吧。

28.

Please don't close the door.

请不要关门。

29.

I play baseball with them.

我和他们一起打棒球。

30.

Alex wasn't hungry then.

那时亚历克斯并不饿。