题目

如图，在光滑水平面上，放着两块长度相同，质量分别为M1和M2的木板，在两木板的左端各放一个大小、形状、质量完全相同的物块，开始时，各物均静止，今在两物体上各作用一水平恒力F1、F2，当物块和木板分离时，两木板的速度分别为v1和v2，，物体和木板间的动摩擦因数相同，下列说法正确的是 (   ) A．若F1＝F2，M1＞M2，则v1 ＞v2，； B．若F1＝F2，M1＜M2，则v1 ＞v2，； C．若F1＞F2，M1＝M2，则v1 ＞v2，； D．若F1＜F2，M1＝M2，则v1 ＞v2，；阅读下面短文，掌握其大意，然后从所给四个答案中选择最佳答案。 　　It was ten o'clock 1, and the last bus 2 at the gate of a park. An old woman got out, and the conductor was going to ring the bell for 3 to start the bus again, when he saw a small boy 4 at the bus stop. 　　“What's the matter?”the bus conductor said to the boy. 　　“My mother gave me ten pence(便士) to go home by bus after I finished playing football in the park with my friends,”the small boy answered,“but I've 5 it, so now I have to walk all the way home.” 　　“That's all right,”said the conductor.“Come on. 6 you home.” 　　The small boy thanked him, 7 the bus and sat down near the door. The conductor rang the bell. Then the bus started.“How 8 are you going?”asked the conductor. The boy told him the name of the place where he lived. It was about two miles away, and 9 would have cost (花费) three pence if the boy had the money to pay for it. 　　The conductor went to give some other people on the bus their tickets, and when he came back a few minutes 10, he saw that the small boy was crying again. 　　“And what's the matter 11 you now?”the conductor asked.“You are on your way home, aren't you?” 　　“Yes, I am,”answered the boy,“but what about my change? You haven't given that to me yet. You should give me 12.” 1． [　　] A．in the morningB．at noon C．at nightD．in the afternoon 2． [　　] A．had just stoppedB．has just stopped C．had just leftD．has just left 3． [　　] A．the conductorB．the boy C．the driverD．the old woman 4． [　　] A．cryB．cried C．cryingD．to cry 5． [　　] A．droppedB．forgot C．lostD．left 6． [　　] A．bringB．take C．carryD．show 7． [　　] A．got offB．got up C．got onD．got in 8． [　　] A．longB．far C．soonD．often 9． [　　] A．the ticketB．the seat C．the busD．the chair 10． [　　] A．beforeB．after C．earlierD．later 11． [　　] A．aboutB．of C．fromD．with 12． [　　] A．seven penceB．ten pence C．three penceD．no pence