我有时下班后去看电影。

11. Not all sharks are alike.

并不是所有的都相似。

Alive adj.  意思为“相同的;相像的”常做表语。

They were born on the same day. The two brothers are very much alike.

他俩出生于同一天。这兄弟俩长得很像。= They were born on the same day. The two brothers are very like.

他俩出生于同一天。这兄弟俩长得很像。

注意：like 之前可以用very 来修饰，但是alike之前则不行。另外，alike也可以用做副词。如：

You and I think alike.

你和我的想法一致。

Great minds think alike.

英雄所见略同。

12. … but many sharks feed on fish, other sea animals, smaller sharks and sometimes people.

……许多鲨鱼以鱼和其他的海洋动物，较小的鲨鱼为食，有时还以人为食。

Feed on sth. 以……为食

Cows feed on hay.

奶牛吃干草。

The children always feed on the best of food.

孩子们常常吃最好的食物。

13. It is said that one of the most dangerous sharks is the great white shark.

据说有一种最危险的鲨鱼是大白鲨。

It is said …据说……

It is said that you are good at operating computers.

据说你很会操作电脑。

It is said that the sports meeting will be put off till next Thursday.

据说运动会会推迟至下周四举行。

类似的句型还有：

It is thought that … 据认为……

It is proved that …  据证明……

It is known that …  众所周知……

It is suggested that …据建议……

It is reported that … 据报道……

It is announced that …据宣布……

It is required that … 据要求……

It is required that we work eight hours a day. Sometime we work till midnight.

据要求我们一天要工八个小时。有时我们工作到半夜。

It was demanded that the working conditions be improved as soon as possible. But nothing is different, just like what you can see now.

根据要求，工作条件要尽快的改进。但是，如同你看到的，什么都没改变。

关于现在完成时态的归纳

1. 现在完成时态的结构have/has+过去分词

2. 现在完成时涉及两个时间概念。一是过去，二是现在。谓语动词虽然所表示的动作发生在过去，但是该时态所强调的还是对现在的影响或结果。关键在于这种影响和结果正是说话人的兴趣所在。因而，该时态通常不带有时间状语。如：

The boy has come back.

孩子回来了。(意思是说孩子在家。)

I’ve lost my pen.

我把钢笔给丢了。(意思是说我现在没有钢笔用。)

3. 现在完成时态还可以用来表示开始于过去，且该状态一直延续至今而且还有可能继续下去的可能性的情况。谓语动词的动作通常是可持续的。如：

I have lived here for more than twenty years.

我在此住了二十多年了。

Nothing has happened ever since.

打那以后就什么也没有发生过，

4. 非延续性动词用于现在完成时态的时候，通常不带表示时间段的时间状语，因此不和for或者since连用。例如，不能说：

I have bought the house for two years / since two years ago.

而应当说：I bought the house two years ago.

或者说：I have had the house for two years.

或者说：It’s two years since I bought the house.

但是非延续性动词的否定式可以和表示一段时间的时间状语连用，表示这种动作的否定状态的延续。如：