A:血浆
B:血小板
C:红细胞
D:白细胞
如图,在三棱锥P﹣ABC中,D,E,F分别为棱PC,AC,AB的中点,已知PA⊥AC,PA=6,BC=8,DF=5.求证:
(1)直线PA∥平面DEF;
(2)平面BDE⊥平面ABC.
It's 8:00. It's time ________ watch TV.
What about____ (play) football with me?