喷嘴吸口的变化范围是怎样的？
参考答案：
内径1~1.5mm。第一喷嘴吸口长度6~15mm，第二喷嘴吸口长度大于5mm。
The headmaster said the School Air Festival will be put off ___ the bad weather. [ ]
A. because
B. for
C. because of
D. thanks for
外感风湿所致头痛是
A．胀痛B．隐痛C．刺痛D．重痛
