双转子皮带张力，可以通过（）来调整。
A.改变皮带长度
B.更换齿轮
C.调节涨紧轮
D.加辅助点
参考答案：C
Jackie Chan is a great actor. He has _____ his fans. [ ]
A. taken care of
B. won the hearts of
C. been afraid of
D. been proud of
简述工作环境分析的内容。
