19世纪60年代，通过对当时发现的63种元素采用科学的分类方法，研制出世界上第一张元素周期表的科学家是（ ）
A：戴维
B：道尔顿
C：门捷列夫
D：阿伏伽德罗
下列有关溶液的说法中，正确的是 （）
质量70kg的消防员背负10kg的装备沿竖起金属杆匀速下滑，此时消防员所受的摩擦力大小是____N，方向是____．（g取10N/kg）
—Let's play basketball ___________ Sunday afternoon.
—Sounds great!
A: Hello, Mike.
B: Hello, Lucy.
A: ____
B: I'm feeling better now.
B: He said I had got a bad cold.
B: No, I can't. I have to stay in bed for a few days.
B: Could you help me with my lessons when I am well?
A: Sure. ____
B: Thank you.
A. What's wrong with you?
B. I hope you'll be better soon.
C. Can you come to school today?
D. How are you today?
E. I'm sorry to hear that.
F. What did the doctor say?
G. Are you feeling better now?
