A:T2噬菌体中含32P的成分是磷脂分子和DNA分子
B:采用搅拌和离心手段,是为了把蛋白质和DNA分开,再分别检测其放射性
C:如果离心前保温时间过长,会导致上清液中的放射性升高
D:该实验结果说明DNA是主要遗传物质而蛋白质不是遗传物质
Once there was a king. He liked to write stories. He thought his stories were good, so he like to show them to people. As people were afraid of him, they all said his stories were very good. One day, the king showed some of his best stories to a famous writer. He wanted the writer to praise(赞美)these stories. But the writer said his stories were so bad that he should throw them into the fire. The king got very angry and sent him to prison(监狱). After some time, the king set him free and ordered him to come to his palace(宫殿). Again he showed some of his new Stories and asked what he thought of them. After reading them, the writer at once turned to the soldiers and said, "Take me back to the prison."
—Look at your hands, John. ______ of them is clean.—OK, I'll wash them at once.
喜马拉雅山的形成原因是( )
“几只蒸汽船,惊破太平梦!”日本对此做出的反应是( )①激发斗志,维护民族独立 ②改革幕政,实现富国强兵③对外开放,学习西洋之法 ④推翻天皇,建立民主政权