问题
选择题
The pupils here_____ all kinds of exercises every day in the past few weeks.
A．keptbusydoing
B．keepondoing
C．havekeptbusydoing
D．havebeenkeptbusydoing
答案
答案：D
keep sb.busy doings sth.表示"使某人忙于"，完成时的被动形式应为have been kept busy doing sth.。