问题 问答题 简答题

简述藻类的生活史类型。

答案

参考答案:

藻类的生活史有营养生殖型、无性生殖型、有性生殖型和无性、有性生殖混合型四种类型。

1.营养生殖型:生活史仅有营养生殖,只能以细胞分裂的方式繁殖。如:蓝藻、裸藻。

2.无性生殖型:孢子不经结合,直接产生子代的生殖方式,没有有性生殖和减数分裂。如小球藻。

3.有性生殖型:有双相型和单相型;前者如:硅藻;后者如:水绵和轮藻。

4.无性、有性生殖混合型:(1)生活史中无世代交替,如衣藻、团藻;(2)生活史中有世代交替,分同形世代交替(如石蒓)和异形世代交替(如海带)。

阅读理解

One of the greatest sources of unhappiness, in my experience, is the difficulty we have in accepting things as they are.

When we see something we don’t like, we wish it could be different -- we cry out for something better. That may be human nature, or perhaps it’s something that’s ingrained(根深蒂固的)in our culture.

The root of unhappiness is that we decided we didn’t like it in the first place. We’ve judged it as bad, rather than saying, “It’s not bad or good, as it just is.”

An example: in my recent post(帖子), A Beautiful Method to Find Peace of Mind, quite a few commentators thought my outlook was negative, pessimistic, or fatalistic(听天由命的)... because I said you should expect people to mess up, expect things to go differently from what you planned. Above all, you should embrace that.

It’s too negative to expect something to go wrong, they said. However, I think it’s only negative if you see it as negative, or if you judge it as bad.

Instead, you could accept it as the way the world works -- as the way things actually are. And try to understand why they are that way.

Does it mean you can never change things? Not at all. But changing things is not because you can’t accept things as they are, but because you enjoy the process of change of learning and growing.

Can we make this world a better place? Again, that’s an assumption that it’s a bad place fight now. But instead, you could say the world is just what it is -- and that’s neither good nor bad. You can say that you’ll continue to try to do things to help others, to grow as a person, to make a difference in this world -- not because you’re such a bad person now, but because that’s the path you choose to take, because you enjoy that path.

As you catch yourself judging, and wishing for different -- try a different approach: accept, and understand. It might lead to some interesting results.

小题1: Which of the following statements is correct according to the author?

A.We can never change things because we can’t accept them.

B.We shouldn’t try to do whatever we can to help others and make a difference.

C.It’s wrong of you to expect things to go differently.

D.There is nothing either good or bad, but thinking makes it so.小题2: What’s the main idea of the whole passage?

A.The world is a good place for us to live in.

B.Unhappiness comes from what we want to be different.

C.You might as well accept the world as it is and try to embrace it.

D.Let’s make the world more beautiful.小题3:Where does the passage probably come from?

A.A novel.

B.A news story.

C.A travel guide.

D.A magazine.

单项选择题