常压下空气温度为25℃时,其声速度为()m/s。
A.330
B.335
C.340
D.345
参考答案:C
解析:
由声速公式
经行情志异常的病因下列哪些是正确的
A.外感寒邪
B.郁热
C.情志内伤
D.房劳多产
E.痰火
— What field will your son go into after graduation from Nanjing University?
— I'm not quite certain, but he ________ a good teacher of English. [ ]
A. promises
B. becomes
C. makes
D. proves