In covalent bonding, atoms share electrons.在共价键联中, 原子共有电子.Crystals may be classified as either ionic or covalent by analogy with molecules.与分子的情况一样,晶体也可以分为离子键型和共价键型.Ceramics primarily have ionic bonds, but covalent bondi...
她的表情隐在阴影中，很难读懂。Under the shaded light her expression was difficult to read.艾森豪威尔离开白宫，退隐到他在葛底斯堡的农场。Eisenhower left the White House and retired to his farm in Gettysburg.杰伊点点头，笑容慢慢隐去了。Jay nodded, his smile fading....
Her name was expunged from the list.她的名字已从名册上除掉.His name is expunged from the list.他的名字从名单中被除掉了.His name was expunged from the record books.他的名字被从档案簿中删去了。The revolutionaries expunged domestic opposition...革命者肃清了国内敌对势力。...