—Why are you standing here Mrs. White?—Im waiting for my son. He back from school.A. ha

问题补充：

—Why are you standing here, Mrs. White?

—Im waiting for my son. He back from school.

A. hasn come B. won come C. doesn come

答案：

解析：句意：你为什么站在这儿？怀特夫人。——我在正在等我的儿子。他还没有放学回家。结合语境可知本句描述的是一直持续到现在的动作，故用现在完成时态，选A。