A:豆浆
B:Fe(OH)3胶体
C:食盐水
D:烟、云、雾
It is illegal to read people's private letters without ____(许可).
人在吸气时,肺和肺内气压的变化是( )
读“东南亚略图”,回答下面小题。
②∵ (x−13)2 ≥0,∴ (x−13)2 + 12 >0.
模仿上述方法解答:
求证:
_______ Mr. Smith is not rich, ________he always gives money to the poor.