碱金属在化学反应中容易失去外层电子成为( )价的阳离子。
A.+2
B.+1
C.+3
D.+1或+2
参考答案:B
With everything needed________, she went out of the shop, with her hands full of shopping bags. [ ]
A. bought
B. buy
C. to buy
D. buying
用于化学运输工具的槽罐以及其他容器,应由专业生产企业定点生产,并经检测、检验合格,方可使用。