检查架空金属管道进人建筑物前每隔()接地一次,进一步检查连接质量,连接导体的材料和尺寸。
A、20m;
B、25m;
C、30m;
D、35m。
参考答案:B
It is necessary that we should spend one hour _____ English every morning. [ ]
A. practice to read
B. practice reading
C. practicing reading
D. practicing to read
通过哪些方式扫除青壮年剩余文盲?