每个矿井都必须建立测风制度,至少每()天进行一次全面测风。
参考答案:10天
When I walked past the street, seeing the children playing happily, their happy laughter _______memories of my childhood.
A.called in
B.called for
C.called on
D.called up
哪一点不利于行销自己()
A.自信
B.勇气
C.说服力
D.骄傲