阿米巴痢疾的传染源主要为()
A.携带包囊的苍蝇
B.曾患阿米巴痢疾但已痊愈者
C.携带包囊的蟑螂
D.包囊污染的食物与水
E.粪便持续排包囊的带虫者
参考答案:E
下列程序段执行结果为( )。 x=5 y=-6 If Not x>0 Then x=y-3 Else y=x+3 Print x-y;y-x
A.-3 3
B.5 -9
C.3 -3
D.-6 5
We are at your service. Don’t _______ to turn to us if you have any further problems.
A.desire
B.manage
C.hesitate
D.seek