【单选题】—Did Alan enjoy seeing his old friends yesterday? ? —Yes, he did.He ______ his old friends for a long time.
【单选题】How did ancient people build these cities?
A.
They used basic tools.
B.
They had sophisticated tools.
C.
They did not use any tools.
【单选题】( ) 5.How much did you pay for that book?
【单选题】有共同目的、明确分工和彼此协调、合作的游戏称为( )。
【判断题】在单管放大电路中,若VG不变,只要改变集电极电阻Rc的值就可改变集电极电流Ic的值
【单选题】当晶体管在发射结加正偏电压,集电结加反偏电压,则晶体管工作在哪个区域?
【单选题】—Did Alan see his old friends yesterday? —Yes, he did. He his old friends for several years.
【判断题】在单管放大电路中,若Vg不变,只要改变集电极电用Rc的值就可改变集电极电流Ic的值。