S1. The reason why many production processes were taken over by the marketplace was that _____.

A．She did better on the quiz than the man did.
B．She did not have to take the quiz.
C．She has not yet received her grade on the quiz.
D．She did not do well on the quiz.

A．He is too sick to take his brother to the airport.
B．He picked up his brother last night.
C．His brother’s flight was canceled.
D．His brother has changed his plans.