蓄电池的加液孔盖必须拧紧,而且盖上的通气孔必须畅通,否则蓄电池在充电过程中,内部会因()而导致()。
参考答案:气体的产生;爆裂
关于接地线设计正确的说法是()。
A、接地线可以从户外架空引入,但必须全程注意多选择接地点可靠连接;
B、接地线不宜与信号线平行走线或相互缠绕;
C、接地线应选用铜芯导线,如无条件可使用铝材;
D、保护地线应选用黄绿双色相间的塑料绝缘铜芯导线;
E、保护地线上严禁接头,严禁加装熔断器或开关;
F、接地端子必须经过防腐、防锈处理,其连接应牢固可靠;
When shall the stand-on vessel change course and speed?()
A.the stand-on vessel may change course and speed at any time as it has the right of way
B.after the give-way vessel sounds one blast in a crossing situation
C.when action by the give-way vessel alone cannot prevent collision
D.when the two vessels become less than half a mile apart