题目

It was Monday. Mrs. Smith's dog was hungry, but there was not any meat in the house. Considering that there was no better way. Mrs. Smith took a piece of paper, and wrote the following words on it, Give my dog half a pound of meat. Then she gave the paper to her dog and said gently, Take this to the butcher. And he's going to give you your lunch today. Holding the piece of paper in its mouth, the dog ran to the butcher's. It gave the paper to the butcher. The butcher read it carefully, recognized that it was really the lady's handwriting and soon did it as he was asked to. The dog wa下图中给出某一时刻t的平面简谐波的图象和x=1.0m处的质元的振动图象，关于这列波的波速v、传播方向和时刻t可能是A．v=1.0m/s，t=0B．v=1.0m/s，t=6sC．t=3s，波向x正方向传播D．t=5s，波向x正方向传播