_______ he is in the school library now. [ ]
A. Maybe
B. May
C. Be
D. May be
答案:A
对UV法进行精密度考查时,试验数据的相对标准差一般不应大于
A.C2%B.99.7%~100.3%C.98%~102%D.1%E.0.2%
装载机的作业灯,应能照清铲斗的作业情况。