两圆C1:x2+y2+4x﹣4y+7=0,C2:x2+y2﹣4x﹣10y+13=0的公切线有( )
Taste the lemon. It's _________.
一棵大树高10____ 一块玻璃厚1____
我家房子面积大约是120____ 一张电话充值卡面积约20____
Stop and wait at a yellow light.