I had a wish to go abroad for a very long time．   小题1:   Now I’m studying in the USA． My wish comes true but I am not happy here． I want to go back to China because I hate the food in the USA．    小题2:They also like fast food and fried chicken very much． But I don’t like such food．   小题3: ． There are many different kinds of food in China．   小题4:So, I often go to the Chinese restaurants in America． The food there is nice but it is very expensive In fact   小题5: ．

A．But I have no chance at all

B．the American people also like Chinese food very much．

C．I like Chinese food

D．People in the USA eat a lot of bread．E． Finally a good chance came．          

F． They are all very delicious．

一平面简谐横波的波动表达式为y=0.002cos（400πt-20πx）（SI）。取k=0，±1，±2，...，则t=1s时各波谷所在处的位置为：（）。

A.

B.

C.

D.