A:available
B:convenient
C:free
D:reliable
– Shall we go and have a picnic at the weekend?– _____ the weather report says there might be a cold front by then.
在进化过程中,直立行走的出现具有重要意义,它使得( )
如图1,在□ABCD中,设∠ABC=α,□ABCD的面积为s,s与α之间的关系如图2所示,则m=____.