问题

n this way, directed by theteacher, ______work out the problem the day before.
A:had they
B:they could
C:could they
D:did they
B:they could
C:could they
D:did they
正确答案是:
同类题型
doyou know so much about the UFO?—I usually get the information by surfing theInternet.
________carefully if any change occurs when doing experiments in the lab.
The little girl could look after though she was only five years old.
______ you got to know I traveled to the USA——Through one of your colleagues.
Do you write a report ______ an animal _______ dangerfor the club