当O2p达到最大时,则()。
A.相关系数大于1
B.相关系数大于0
C.相关系数等于1
D.相关系数等于-1
参考答案:C
选择正确问句。
1. It's windy and cloudy.[ ]
A. What can you do?
B. How's the weather?
C. May I help you?
2. To the shop.[ ]
A. What are you doing?
B. What do you want to do?
C. Where are you going?
3. He is driving a car.[ ]
A. What are they doing?
B. What can he do?
C. What is he doing?
下列关于实验操作的叙述中,正确的是 ( )
A.过滤时,要使漏斗下端的管口靠紧烧杯内壁
B.用酒精灯给量筒里的液体加热
C.用燃着的酒精灯去点燃另一只酒精灯
D.为了节约药品,实验后剩余的药品要立即放回原瓶