Officials of the U.S. government haven’t found the reasonable explanation for ______.

A．Native customs in Germany when meeting someone for the first time.
B．Questions that one has to answer when going through the customs.
C．The popularity of online shopping using one’s personal computer.
D．The most effective method of learning the German language.

A．The man is surprised that Judy chose that agency.
B．The man wonders why Judy still keeps her job.
C．The man doesn’t know when Judy’s classes started.
D．The man doubts Judy makes much money now.