图为一列简谐横波的波形图，其中实线是t1=1.0s时的波形，虚线是t2=2.0s时的波形，已知t2-t1=
T．则x=0处质点的振动图象为图中的（ ）1 4
A．
B．
C．
D．
A、由振动图象知，t1=1s时刻质点振动方向沿y轴负方向，t2=2s时刻质点处于负向位移最大处，与波动图象两个时刻O点的振动情况一致．故A正确．
B、由B图读出，t1=1s时刻质点振动为沿y轴正方向，t2=2s时刻质点处于正向位移最大处，与波动图象两个时刻O点的振动情况不一致．故B错误．
C、t1=1s时刻质点处于正向位移最大处，t2=2s时刻质点经过平衡位置沿y轴负方向运动，与波动图象两个时刻O点的振动情况不一致．故C错误．
D、t1=1s时刻质点处于负向位移最大处，t2=2s时刻质点经过平衡位置沿y轴正方向运动，与波动图象两个时刻O点的振动情况不一致．故D错误．
故选A．
| 完形填空 | |||
| One day a Frenchman goes to New York. He 1 a word of English. When he arrives in New York, he 2 a taxi to the hotel. It's Sunday,so the Frenchman wants to go out 3 a walk. He walks along the streets and then 4 , for he remembers he doesn't know the name 5 the street, so he wants to write it 6 . He looks at 7 near the corner of the street, he 8 some words on it and writes them down in his 9 . He walks for a long time. 10 he feels tired and wants to go back to his 11 . He 12 the notebook out of his pocket and 13 the name to a young man. But he doesn't know what the man 14 .Do you know 15 the words in his notebook are? These are the words: No Way Ahead(此路不通). | |||
| ( )1. A. don't know ( )2. A. takes ( )3. A.for ( )4. A.stop ( )5. A.for ( )6. A.up ( )7. A.the window ( )8. A.looks ( )9. A.notebook ( )10.A.But ( )11.A.country ( )12.A.gives ( )13.A.shows ( )14.A.likes ( )15.A.where | B. doesn't see B. rides B.of B.stopping B.of B.down B. the wall B.look at B.pocket B. After B. hotel B.finds B.writes B.wants B.which | C. doesn't know C. drives C. in C. to stop C. in C.on C.the people C.see C.newspaper C.Before C. home C.puts C.puts C.knows C.how | D. not knows D. sit D. at D. stops D.at D. in D.the tree D.sees D.diary D. Then D.street D.takes D.says D.understands D.what |