现有两种元素的原子结构示意图：
乙中x的数值为__________；它们相互形成的化合物是___________（填化学式）。
7；MgCl2
---What were you doing when the UFO ______?
---I ______ a milk shake.
A．reached, made
B．reached, was making
C．arrived, made
D．arrived, was making
存放体温计的干燥储物盒每周清洁（）次
