A:to finish, helping
B:to finish, being helped
C:finishing, helping
D:finishing,being helped
①受精卵中的遗传物质主要来自于染色体;
②受精卵中的细胞质主要来自卵细胞;
③受精时精子全部进入卵细胞内;
④精子和卵细胞的染色体合在一起成为4N条;
⑤受精卵中的染色体一半来自父方,一半来自母方.
---- _________ do you like ping-pong ?
---- Because it is relaxing.
Name: Peter
Student number: 12
Age: 13
Can: draw
____ ____ ____ Peter
____ student number is____.
____ thirteen ____ ____
He's fat
He can ____.