1,-5,13,-29,( )
A.-6l B.-39 C.39 D.61
参考答案:D
解析: 两两相加得到数列:-4,8,-16,(32),是等比数列,所以29+32=61。
已知l1、l2是两条异面直线,α、β、γ是三个互相平行的平面,l1、l2分别交α、β、γ于A、B、C和D、E、F,AB=4,BC=12,DF=10,又l1与α成30°角,则β与γ的距离是______;DE=______.
What _____ he _____ on Sundays? [ ]
A. does, do
B. does, does
C. does, /
D. do, do