25的平方根是( )
A.5
B.-5
C.±5
D.625
∵(±5)2=25,
∴25的平方根是±5.
故选C.
Read and number. (给下列句子排序)
( ) I usually get up at 6:40. When do you go to school?
( ) Me, too. When do you play sports?
( ) When do you get up?
( ) At 3:00 in the afternoon.
( ) At 7:30. How about you?
( ) At 6:30. And you?
装有易燃气体的车辆,距牵引的内燃机车最少隔离()辆。
A.1
B.2
C.3
D.4