在边长是40厘米的正方形中画一个最大的圆,则该圆的半径是[ ]
A.40厘米
B.20厘米
C.10厘米
答案:B
下列哪项职业有害因素与月经异常无关()
A.工业毒物
B.常见农药如有机氯、磷
C.高分子化合物
D.物理因素
E.负重作业,长时间立位
Like some of my classmates, I can't live up to my teachers' expectations,___ , I let them down. [ ]
A. in other words
B. after all
C. what's more
D. more or less