问题

______ in the queue for half an hour, the old man suddenly realized he had left the check in the car.

A:Waiting
B:To wait
C:Having waited
D:To have waited

正确答案是：

同类题型

Han Han is a popular writer. His new book _________ last September.

_______and three is ten.

meant to meet you at the airport this morning,but I was too busy for I_______ a report

No one is so ____ about his joy as Doctor Li.—-You are right. He devotes all his time and energies to his cause.

What the science teacher does and says ofgreat importance to college students.