SE卷烟机烟支切口歪斜的原因之一是（）。
A.切烟管间隙过大
B.切烟管间隙太小
C.切刀太长
D.切刀太短
参考答案：A
Almost all of his time ______ experiments, he has no time to visit his parents.
A．devoted to do
B．devoted to doing
C．devoting to doing
D．is devoted to doing
感染性休克模型制备，下列哪项动物最敏感（）。
A.猫
B.猪
C.小鼠
D.狗
E.兔
