49的平方根是( )。
±7
It is reported that the ______ in Libya is hotting up.
A.strength
B.violence
C.power
D.activity
古人说:“羌笛何须怨杨柳,春风不度玉门关”中的“春风”指 [ ]
A、冬季风
B、东北风
C、夏季风
D、台风