哮证发作的病因病机关键是（）
A．宿痰内伏于肺
B．外邪侵袭，触动伏痰
C．痰气相激，气道被阻
D．邪客于肺，气道不利
E．脏腑虚弱，气失所主
参考答案：C
You can read this kind of English novel because there are _________ new words in it.
[ ]
A. a little
B. a few
C. little
D. few
东方电机厂QFSN—300—2型汽轮发电机是如何防止绕组结露的？
