A:Come o
B:No worry
C:That’s impossible
D:No problem
He had 2 watermelons yesterday, ____today he had a stomachache. ( )
一粒种子最重要的部分
(Ⅰ)求证EF∥平面PCD;
(Ⅱ)求直线DP与平面ABCD所成角的正弦值.