现场防护员禁止参与其他作业，与使用风力除雪机人员距离不得超过（）米。
A.1
B.2
C.3
D.4
参考答案：C
我国经济发展的关键环节是( )。
A．农业B．教育和科学C．工业D．商业
Mary often does some translation work to earn extra money, which _______ half of her income. [ ]
A. makes up
B. counts on
C. accounts for
D. consists in
