【题目】It is obvious to the students _______ they should get well prepared for their future.
A.whichB.thatC.whetherD.as
在线课程【答案】B
【解析】
考查主语从句。句意：学生们显然应该为他们的未来做好充分的准备。此句用it做形式主语指代主语从句“___they should get well prepared for their future”，引导词在主语从句中不做任何成分且无意义，所以用that引导。故选B项。