【判断题】Silk has also brought the ancient Chinese civilization overseas and it serves as the "cultural messenger" of Chinese civilization.
【单选题】某哺乳动物一个初级精母细胞经过减数分裂产生了染色体数目全部不正常的配子,最可能的原因是()
【单选题】They also have a camera ______allows you to take and share photos and video.
【简答题】Everyone wants to be successful. As a student, you also want to have success at school, no matter w __ 小题1: __ you’re good at studies or not. But it’s d i fficult to learn all the lessons well because...
【单选题】听力原文:W: Bob, would you please come in for a while? Please also bring along the minutes of yesterday's management meeting. M: Of course, Madame. Here is the minutes of the meeting. The meeting was dela...
【多选题】近代上海社会心态发生根本转变,主要体现在( )。
【判断题】Chinese civilization is the oldest human civilization in history.
【单选题】听力原文:W: Good morning, Chuck, are you also here waiting for Professor Johnson? M: Oh, yes. Good morning, Lori. The professor asked me to come for an interview. Do you know about the job working as a te...
A.
On his way home from school.
C.
Doing his English assignments.
D.
Waiting to see Prof. Johnson.
【单选题】某哺乳动物的一个初级精母细胞经过减数分裂后产生了染色体数目全部不正常的配子 , 最可能的原因是 ( )
A.
. 该细胞减数第一次分裂时 , 有一对同源染色体不发生分离 ; 减数第二次分裂正常
B.
. 该细胞减数第一次分裂时 , 四分体中的非姐妹染色单体交叉互换 ; 减数第二次分裂正常
C.
该细胞减数第一次分裂正常 , 减数第二次分裂时 , 一个次级精母细胞分裂正常 , 另一个分裂不正常
D.
C . 该细胞减数第一次分裂正常 , 减数第二次分裂时 , 一个次级精母细胞分裂正常 , 另一个分裂不正常