仪表风停时，混氢控制阀的阀位（）。
A、全开
B、全关
C、不变
D、剧烈波动
参考答案：C
—We are going to have a picnic next Sunday.
—_______________________
A．The same to you.
B．Help yourself.
C．Have a good time.
D．I don’t agree with you.
下列关于铁在小肠被吸收的叙述，正确的是
A．铁都以Fe3+的形式被吸收
B．铁主要在十二指肠和空肠被吸收
C．胃酸及维生素C可抑制铁的吸收
D．血红蛋白中的铁不易被吸收
