已知a、b∈R，且ab≠0，则下列结论恒成立的是（ ）
A. What about you?
B. What shall we take?
C. How shall we get there?
D. Would you like to go with me?
E. When and where shall we meet?
F. Shall I tale some food?
G. What are you going to do?
A: Hi, Tom. The weekend is coming.____
B: Nothing much. ____
A: I'm going to watch the sports meet.____
B: I'd love to. ____
A: A bottle of water and a camera.
B: ____
A: Let's make it half past seven at the school gate.
B: OK. See you tomorrow.
A: See you.
相同质量的CO和CO2，则CO和CO2所含的氧元素质量比为____，若CO和CO2所含的氧元素质量相等，则CO和CO2质量比为____。
｝中，已知
，
，则
等于（ ）来源:Z.xx.k.Com