一道英语选择题的疑问,为什么选A不是选择B.
The first thing you should have learned at collage is to work on your own. it's time you() able tomanage yourtime.
A:Were B:should be
正确答案是A
可是不明白为什么不是选择B
请告诉:为什么选择这个答案的理由.谢谢