问题

Did you notice someone enter the classroom just now—Sorry, I didn’t. I _____ my lessons at that time.

A:am doing
B:did
C:do
D:was doing;

正确答案是：

同类题型

Time waits for no manBut teenagers won’t realize the value of time until it’s goneDon’t waste your time, __________ you will regret it

he consequences of the chemicalleaks, the specialists haven’t given final conclusion before they obtainaccurate statistics.

ung man invited the lady to dance withhim, but she ______ his invitation．

It should be _____ that the civil servant should be dismissed for drunk driving .

Jack, you seem in high spirits.—__________ We won the match 4-0.