行人通过的输送机尾设()。
A.护栏
B.盖板
C.过桥
参考答案:B
计算8m-8n的值为( )
A.64mn
B.8mn
C.64m+n
D.23(m+n)
As the goods ____ within the scope of our business activities, please contact us immediately.
A. falls
B. fall
C. fell
D. falling