① ____ A. This is cow.
② ____ B. The pig goes “oink, oink” .
③ ____ C. What’s that? It’s a chick.
④ ____ D. Eat a cake.
核电站中可用硼酸(H3BO3)吸收中子,阻断核辐射。硼酸中硼元素的化合价是( )
受损元素周期表中某元素的残留信息如图所示,根据残留信息得出的下列说法中错误的是( )
We had a very good time at the evening party.