铁的主要吸收部位是()
A.胃
B.十二指肠
C.十二指肠及空肠上段
D.回肠
E.肝脏
参考答案:C
— “ The music is too loud. Could you please turn down the radio a bit?”
— __________________
A.Sorry. I didn’t know you were reading.
B.Thank you. It’s very kind of you.
C.Don’t trouble. I like music.
D.Oh, it’s an honor for me to do so.
清管器收发筒的直径和管道公称直径相比大()等级。
A、l~2
B、2~3
C、3-4
D、4~5