Excel工作表最多可有（）列。
A、65535
B、256
C、255
D、128
参考答案：B
It was raining hard, but by the time the class was over, the rain _______.[ ]
A. had stopped
B. was stopping
C. stopped
D. would stop
JAksonLAB的Little于1909年采用近亲交配方式培育出了第一近交系（）。
A、DBA
B、CBA
C、C3H
D、BALB/C
