主要由一氧化碳和氮气组成的煤气是（）煤气。
参考答案：高炉
–Peter has good grades in all his subjects, but he never shows off.
–I agree. He is very _________.
A．easy-going
B．imaginative
C．modest
D．generous
豨莶草具有的功效是（）
A.化湿和胃
B.凉血消肿
C.活血止痛
D.清热解毒
E.清退虚热
