人的卵细胞受精后,从受精卵开始到出生之前的这段时间称( )
A:卵的发育
B:胎儿发育
C:胚胎发育
D:受精卵发育
补全对话,每空一词。
A: ____ time do you usually get up, Bob?
B. I usually get up ____ 6 o'clock.
A. So early? What do you do then?
B: I ____ my teeth and ____ a shower. Then I eat my breakfast.
A: ____ do you go to school?
B: At 8 o'clock.