用适当的数字和化学符号填空:
(1)镁离子 _________
(2)2个铁原子 _________
(3)水分子 _________
(1)Mg2+
(2)2Fe
(3)H2O
早期中心型肺癌诊断阳性率较高的方法是()
A.胸片
B.普通断层片
C.胸部CT
D.纤维支气管镜
E.胸部透视
their problems can make them worry, I still have ways to help them out.
A.Because, so
B.Though, /
C.Either, or
D.Whether, or