The fill and overflow valve is used to fill the tank to the capacity determined by a standpipe, this valve is operated by a handle.在以上句子中，提到了这样一个内容，即，“竖管确定水箱的容量”。
A.1正确答案A
The fill and overflow valve is used to fill the tank to the capacity determined by a standpipe, this valve is operated by a handle.在以上句子中，提到了这样一个内容，即，“竖管确定水箱的容量”。
A.1正确答案A
