The research is so designed that once________nothing can be done to change it. 
#5001
A
begins
B
having begun
C
beginning
D
begun
推荐题目
“It looks as if he were drunk.” “So it does. _____.”
#4953
A
He’d better give up drinking
B
He shouldn’t have drunk so much
C
Health is more important than drink
D
I wonder why he is always doing so