问题补充：
The students of Senior 3 are now under great pressure for it will be just one year they take the Entrance Examination.
A. since
B. after
C. before
D. when
答案：
A. since
B. after
(答案→)C. before
D. when
解析：句意,上文,高三的学生现在都很大压力,下文，因为只有不到一年的时间就要参加高考了。考查句型it was/will be +一段时间+before+clause ,没过多久。。。就 ，从句常用一般现在时或一般过去时。since意思是自从.常和完成时态连用，after在。。。之后，when当。。。时候。故选C.
