《中华人民共和国药品管理法》立法的核心目的是( )
A.药品广告管理
B.维护人民身体健康
C.保证药品质量
D.加强药品监督
E.药品价格管理
参考答案:B
阅读短文,然后判断对(√)错(×)。
I have a friend. She is a girl. Her hair is short and yellow. Her eyes are blue. She has a big nose and a little
mouth. She is pretty.
( ) 1. Her hair is long.
( ) 2. Her eyes are green.
( ) 3. Her nose is little.
( ) 4. Her mouth is big.
( ) 5. She is pretty.
请简单说明换热器温差应力产生的原因和常见解决办法有哪些?