There are two one-way valves for water inlet and outlet, which cooperates with floating ball in water tank to play switch role.
进出水口有二个单向阀，水箱内置有浮球装置，该装置和二个单向阀共同起开关作用；
They play eight-man ball, although if a bigger school comes to town they switch numbers with every possession, so that each side can practice its plays.
他们按八人制的规则打球，如果来镇上比赛的学校人比较多，他们就会在每次控球权转换时调整人数，这样双方都能按自己习惯的规则打球。
And solutions often either can't anticipate the specific repository that will be in play or at least need the option to switch at some point down the road.
通常，解决方案不能预期只会使用某个特定存储库，至少需要在开发过程中的某个时点上有可以切换的选项。
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