碗扣式钢管脚手架，一般在立杆距离为1.2m×1.5m时，架高不宜超过（）m。
A.40
B.50
C.60
D.70
参考答案：B
In order to avoid something unpleasant, everyone present should stick to the agreement___________.
A．traditionally
B．accidentally
C．consciously
D．personally
购买力是消费者购买出版物的（）能力。
A.讨价还价
B.货币支付
C.市场寻找
D.分别辨析
