I don't ____ the way to the nearest bank. And you? [ ]
A. understand
B. see
C. know
D. no
答案:C
水射器的效率较低,一般都在()以下。
A.45%
B.35%
C.30%
D.20%
螺上的性能等级标志印在()的端面和侧面。
A、螺杆
B、螺栓端头
C、六角头
D、螺杆外圆