根据短文理解，选择正确答案。

    Do you know pigeons? They are a kind of birds. They are in white and grey. Some people say they are not beautiful but they are cute and smart. Many people keep them as pets. Why do people say pigeons are clever? Because pigeons can take letters from one place to another. And they know the way home. We often see the picture of a pigeons with an olive branch(橄榄枝) in its mouth. We call them peace pigeons. They are the symbol of peace.

下列有关文学常识的表述，有错误的一项是 （     ）

四大洋中，亚洲没有濒临的是（    ）

依次填入下列各句横线上的词语最恰当的一组是(     )
①既然政府还没有发出________，允许做这种事，那就做不得。
②为了避免我们的谈话被人家误解，________闹出什么乱子起见，我得把我们的谈话内容报告校长。
③契诃夫生活在俄国农奴制崩溃和无产阶级革命________兴起的时期。
④这人总想把自己________在壳子里，仿佛要为自己制造一个套子，好隔绝人世。