下列哪种酸在常温下可用来清洗不锈钢加热器和铜锈（）
A、盐酸
B、硝酸
C、磷酸
D、硫酸
参考答案：B
His mother kept telling him to____ his manners at the party.So he became impatient.
A．mind
B．notice
C．watch
D．care
常见的无形资产主要有哪些？
