柴油机燃烧过程中,喷油主要是在()
A.滞燃期
B.缓燃期
C.速燃期
D.后燃期
参考答案:C
—Why are most children under too much pressure?
—Because their parents always compare them _____ others.
A. with
B. by
C. to
探头中使用压电陶瓷晶片的优点是()。
A.激励电脉冲的宽度
B.发射电路阻尼电阻的大小
C.晶片的材料和厚度
D.晶片的机电耦合系数