【单选题】Tomorrow is Dragon Boat Day, so my mother and my grandma __ a big meal for our family in the kitchen.
【单选题】. Can you see the tree _____ we tied our boat last time?
【单选题】关于电磁感应现象,下列说法中正确的是:
A.
闭合线圈放在变化的磁场中,必然有感应电流产生
B.
穿过闭合电路的磁感线条数发生变化时,电路中有感应电流
C.
穿过闭合线圈的磁通量变化时,线圈中有感应电流
D.
闭合正方形线圈在匀强磁场中垂直磁感线运动,必然产生感应电流
【单选题】Our boat floated on (漂流) ,between walls of forest too thick to allow us a view of the land we were passing【21】though we knew from the map that our river must from time to time be passing through chain...
【单选题】There is a fishing boat in front of our ship.()
【单选题】关于电磁感应现象,下列说法中正确的是( )
A.
闭合线圈放在变化的磁场中,必然有感应电流产生
B.
闭合正方形线圈在匀强磁场中垂直磁感线运动,必然产生感应电流
C.
穿过闭合线圈的磁通量变化时,线圈中有感应电流
D.
只要穿过电路的磁通量发生变化,电路中就一定有感应电流产生
【单选题】Our boat was surrounded by a large _________ of dolphins.
【单选题】关于电磁感应现象,下列说法中正确的是 ( )
A.
闭合线圈放在变化的磁场中,必然有感应电流产生
B.
闭合正方形线框在匀强磁场中垂直磁感线运动,必然产生感应电流
C.
穿过闭合线圈的磁通量变化时,线圈中有感应电流
D.
只要穿过电路的磁通量发生变化,电路中就一定有感应电流产生