In order to finish the experiment successfully, the professor always , for every day the light in his room didn’t go out until 4 a.m.
A. mixed up
B. cleaned up
C. turned up
D. stayed up
网友回答
A. mixed up
B. cleaned up
C. turned up
(答案→)D. stayed up
解析:可联系答.案.网客服索取。