问题
单项选择题
一个DNA分子经过4次复制，形成16个DNA分子，其中含有最初DNA分子长链的DNA分子有（）
A.2个
B.8个
C.16个
D.32个
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
一个DNA分子经过4次复制，形成16个DNA分子，其中含有最初DNA分子长链的DNA分子有（）
A.2个
B.8个
C.16个
D.32个
参考答案：A
Once upon a time there was a little boy who became very ill.He had to spend all day in bed, unable to ____.Because other children weren't allowed to come near him, he ____ greatly, and spent his days feeling sad and ____. There wasn't much he could do ____ look out of the window.Time passed, and his feeling of ___ just grew.Until one day he saw a strange ____ in the window.It was a penguin ____ a sausage sandwich.The penguin squeezed in ____ the open window, said “good afternoon” to the boy, ____ around, and left. Of course, the boy was very ____.He was still trying to ____ what had happened, and as more crazylooking characters appeared out the window, he burst out ____ and found it hard to stop. The little boy didn't tell anyone about this because who would have ____ him? Even so, those strange characters ended up putting ____ back in his heart, and in his body.Before long, his ____ had improved so much that he was able to go back to school again. There he got to talk to his ____， and tell them all the ____ things he had seen.While he was talking to his best friend he saw something ___ out of his friend's school bag.The boy asked his friend what it was, and he was so ____ that finally his friend had to show him what was in the bag： There, inside, were all the fancydress suits and disguises(假扮的东西) that his friends had been using to try to ____ the little boy up! And from that day on, the little boy always did his best to make sure that no one felt sad and alone.
|