下列推断合理的是（　　）

19世纪后，许多国家尤其沿海国家无可选择地与海洋联系在一起。但近代中国发展海军并未真正认识这一世界大潮，而始终局限于对西方列强炮舰政策的本能反应，呈现出“海患紧则海军兴，海患缓则海军弛”的状态。这体现出近代中国（  ）

下列有关生物进化的叙述中正确的是（　　）

从框里选择填入对话相应空白处的适当选项

A: Hello, this is Ann.Is that Helen ?
B: Yes, speaking.
A:Helen, The happy weekend is coming. ____ 
B: Yes, I’m not busy. I've already finished my homework.
A: ____ 
B: I’ve no idea. What about you ?
A: Let me see. Let's do something interesting and helpful. ____ 
B: Certainly. Where?
A: In the new museum.
B: Oh, I remember. I heard of it last week. ____ 
A: By bike. It's Saturday tomorrow. The traffic must be heavy, I think.
B: I agree. ____ 
A: At the gate of our school at nine in the morning.