Webof Science数据库支持的逻辑运算符有：（）
A、AND
B、OR
C、NOT
D、Same
参考答案：A, B, C, D
一种商品价格(P)上涨，会引起其替代商品需求量(Q1)的变化，同时也会引起其互补商品需求量(Q2)的变化。下列曲线图中正确反映其变动关系的是（ ）
补全对话（每题2分，共10分）
根据下面的对话情景，在空白处填上一个适当的句子，使对话的意义连贯、完整。
A: Look at this picture. What’s it?
B: Oh, it’s a robot!
A: You’re right. it’s the newest robot in the world.
B: ①______________?
A: It can help with housework.
B: ②______________?
A: Of course. Besides(除了) sweeping the floor, it can also take care of kids and old people.
B: ③______________?
A: No, I won’t. I can’t afford it.
B: ④______________. Is it very expensive?
A: Yes. It’s 50,000 dollars. But we can have a look at it tomorrow. it is on show in the Science Museum.
B: Sounds great. ⑤______________?
A: What about at my home at 9:00 am?
B: OK. See you then.
