对于模数相同的齿轮,若齿数越多,齿轮的几何尺寸()
A.越大
B.越小
C.不变
参考答案:A
I _______ to the party if I________tomorrow.
A.will go; will be invited
B.will go; am invited
C.go; will invite
D.go, have been invited
头索动物一个显著的特征就是脊索终生存在,且达到头部。()