My uncle is _____ engineer. He works very hard. [ ]
A. the
B. a
C. an
答案:C
设函数y=(1-2k)x2,当x>0,y随x地增长而增大,则k=______.
为防止柴油机排气污染,净化环境,柴油机出厂要做()检验。
A.工作油压、怠速油压
B.油门封定点烟度
C.自由加速烟度测量