机构是否存在死点位置与机构取哪个构件为原动件无关。
A. 对
B. 错
心字底的书写要点有
A. 三个点呈一条右上倾斜的线
B. 垂点和卧钩的起笔在一条水平线上
C. 心字底与上面的字左边齐平,右边要突出
D. 卧钩有个明显的转弯要好看些
Read Text C and then finish the exercises.a. they invented it b. they practice it a lot c. they do it bettera. a sight of breathtaking beauty __________b. an outstanding achievement __________c. an act of abominable cruelty __________d. an unforgivably stupid misjudgement __________5) Why do most foreigners find the English understatement hard to get?
实验测得某有源二端线性网络的开路电压为10V。当外接3Ω电阻时,其端电压为6V,则该网络的等效电压源的参数为()。
A. US=6V,R0=3Ω
B. US=8V,R0=3Ω
C. US=10V,R0=2Ω