— Do you think their table tennis team will win the first place at the coming Asian Games?

— _____. Ours is much stronger than theirs.[ ]

A. Of course

B. It depends

C. Don't mention it

D. By no means

四名运动员参加4×100米接力，他们100米速度分别为v₁，v₂，v₃，v₄。不考虑其他影响因素，他们跑400米全程的平均速度为（）。

A．A

B．B

C．C

D．D