晶闸管导通必备的条件为()。
A.阳极加正向电压
B.阴极加正向电压
C.阳极加正向电压,同时在门极上加正向触发电压
D.同时在门极上加反向电压
参考答案:C
设集合M={x|0<x≤3},N={x|x(x-2)<0},那么“a∈M”是“a∈N”的( )
A.充分不必要条件
B.必要不充分条件
C.充要条件
D.既不充分也不必要条件
____________the gloves? They’ re very nice. They feel soft and smooth.
A.What do you think of
B.What do you like
C.How do you do
D.How would you like