建立流行病数学模型的首要基础是（）。 A.有极好的数学知识 B.提出模型假设 C.精

根据短文内容回答下列问题。

    The Wilsons decided to go overseas for vacation. They had a family meeting to plan the vacation.

    "First," Mr Wilson said, "we should decide where we are going."

    "I don't agree," Mrs Wilson said, "I think we should decide when we are going first. We don't want

to go to places when they are cold."

     Mr Wilson agreed, so the family's first decision was when to go on vacation. They decided

to go in July.

    "Now we can decide where to go," said Mr Wilson.

    "But, Dad," Ben said, "don't you think that where we go depends on (依赖，取决于) how we go?

If we plan to fly, we can go a long way. If we plan to drive, we can't go far."

     Again, Mr Wilson agreed, and they discussed this. At last they agreed to travel by plane.

     And so the planning meeting went on. The next day, one of Mr Wilson's friends at work asked,

"Where are you going for vacation?"

     "Well," Mr Wilson told him, "we are going in summer by plane, but I don't know where we are going!"

1. Why did the Wilsons have a family meeting?

2. What did they decide first?

3. When did they decide to go? 

4. How did the Wilsons decide to travel? 

5. What they didn't decide？ 

我国历代有作为的统治者都非常重视人才，战国时期的百家争鸣中，主张选举贤能的人治理国家的是

A．孟子

B．墨子

C．庄子

D．韩非

新航路的开辟被国际社会多数史学家认为是人类文明史上最具有转折意义的事件，这主要是指新航路的开辟使[ ]

A．西欧国家开始大规模殖民扩张      

B．西欧国家的思想文化领域受到极大冲击

C．地域性历史开始演变为世界历史    

D．西欧国家发生了商业革命和价格革命

具有升华性的生物碱是( )

A．烟碱
B．麻黄碱
C．川芎嗪
D．小檗碱
E．甜菜碱

库存车的车门侧与另一辆车的车门侧之间距离应大于（）CM。

A.20

B.40

C.60

D.80