问题
选择题
一条染色单体含有1个双链DNA分子,那么四分体时期的1条染色体含有[ ]
A.4个双链的DNA分子
B.2个双链的DNA分子
C.2个单链的DNA分子
D.1个双链的DNA分子
答案
答案:B
一条染色单体含有1个双链DNA分子,那么四分体时期的1条染色体含有[ ]
A.4个双链的DNA分子
B.2个双链的DNA分子
C.2个单链的DNA分子
D.1个双链的DNA分子
答案:B
完形填空。 | ||||
We have a two-day holiday 1 week. We don't have any lessons 2 Saturday or Sunday. So every weekend I have a good 3 . On weekend, I like 4 a trip. I sometimes go to the country with my classmates 5 bus to breathe (呼吸) the fresh air., watch the green hills and blue water, and 6 in the beauty of the country. sometimes I go for a picnic in the open 7 with my friends by bike, we sing and dance 8 there. Sometimes I go to 9 a place of interest with my parents by car. My weekend is always 10 interesting and happy. | ||||
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