简述清棉机天平调节装置的作用原理。
参考答案:
通过天平罗拉与天平曲杆的棉层变厚时,天平罗拉转速对应的变慢;反之,天平罗拉转速变快,使单位时间内的喂棉量保持一致,减少变化。
I ____my CD here and there, but I still can’t find it.
A.have looked for
B.look for
C.will look for
D.was looking for
如图所示电路中,已知I1=0.01μA,I2=0.3μA,I5=9.61μA则电流I3等于()
A.0.31μA
B.0.41μA
C.0.51μA
D.0.61μA