在图中已知通过透镜后的折射光线，请将入射光线补充完整．

图A是在高速公路上用超声波测速仪测量车速的示意图，测速仪发出并接收超声波脉冲信号，根据发出和接收到的信号问的时间差，测出被测物体的速度。图B中P₁、P₂是测速仪发出的超声波信号，n₁、n₂分别是P₁、P₂由汽车反射回来的信号。设测速仪匀速扫描，P₁、n₁、P₂、n₂对应的时间分别为T₁、T₂、T₃、T₄，超声波在空气中传播的速度是v，若汽车是匀速行驶的，则根据图B可知，汽车运动速度为多大?并说明可以根据图B中的哪些量判断汽车运动方向?

补全对话

A:____?

B: I'm reading a book.

A:____?

B: It's about a great player. Her name is Deng Yaping.

A: Is she your hero?

B____. I admire her very much.

A:____?

B:She's won many world competitions, including four gold medals in the Olympic.

A:What did she do after that?

B:She began to study at Tsinghua University in Beijing and then attend university abroad.

Whatever she does ,she never gives up.

A:____

在水溶液中能大量共存的一组离子是（   ）