煤矿用电器设备（I类）表面可能堆积煤粉时，允许最高表面温度为（）℃。
A.120
B.130
C.140
D.150
参考答案：D
人站在地面上，人对地面有压力，该力的受力物体是______，施力物体为______，同时地面也对人产生支持力，该力的受力物体是______，施力物体是______，以上说明力的作用是______．
We have every reason to believe that progress in new technology will ________a more comfortable life.[ ]
A. lead to
B. refer to
C. turn to
D. stick to
