人类成熟的精子中有( )a.23个染色单体 b.46个染色单体 c. 23个DNA d. 46个DNA e .22+X f. 22+Y
A:ace
B:bdf
C:adf
D:acf
判断下列句子与短文内容是否相符。
Hi.I'm an English girl.I'm Jane.I'm 143 cm tall and 42 kg.I studied in Shanghai last year.I had many Chinese friends.My best friend is Liu Ying.She is 161 cm tall and 51 kg.Last weekend we went to a park.We went shopping,then we saw a film.We were very happy.I love my friends.
75,____,____,____,____,____,____,____,____,____,____。
90,____,____,____,____,____,____,____,____,____,____。
某地西侧是西半球东侧是东半球,南侧是热带,北侧是北温带,该地位置是