碱金属原子的价原子具有两种能态.The valence atom of an alkali - metal atom has two states.所有的碱金属都在闭合壳层之外有一单个S电子.All the alkali metals have a single s - electron outside a closed shell.当碱金属光谱显示出不容怀疑的双线结构时,是令人惊奇的.It was surprising when th...
...heart-rending pictures of refugees...令人心碎的难民照片The cries of those imprisoned in the fallen buildings were heart - rending.被困于倒塌大楼里的人们的哭喊声令人心碎.Suddenly, the cat lets out a heart - rending yowl.突然, 那猫发出一声撕心的嚎叫.Heart - re...