根据GB5725-2009《安全网》3.11中定义，把安全网固定在支撑物上的绳，称为（）
A.边绳
B.系绳
C.筋绳
D.连接绳
参考答案：B
He _____the problem _____in his mind for a whole week before he did anything about it.
A．switched; on
B．kicked; up
C．turned; over
D．took; on
如何避免钢液舔电极？
