【单选题】No sooner _____ the boy fall into the pond than he ____ to his feet and went to the rescue.
C.
has he seen… is jumped
D.
did he see… had jumped
【单选题】对称三相负载三角形联结, 电源线电压 =220∠ 0°,如不考虑输电线上的阻抗, 则负载相电压 =( )V。
【单选题】电源线电压对称,三相负载三角形联结时,三相负载上的三相电压( )。
【单选题】Hardly ______ he entered the classroom when the rain began to fall in big drops.
【单选题】下列哪个是 EditText 控件表示文本输入类型的属性
【单选题】下列哪个是 EditText 控件表示文本输入类型的属性
【简答题】He’s working hard for fear that he__________. A.should fall behind B.fell behind C.may fall behind D.would fall behind