A:赫尔希和蔡斯用35S和32P分别标记T2噬菌体的蛋白质和DNA,证明了DNA是主要的遗传物质
B:用含有充足有机物的完全培养基培养T2噬菌体
C:噬菌体侵染细菌实验中,同位素32P标记的一组中,上清液中放射性较强
D:艾弗里提取的DNA掺杂有非常少量的蛋白质,实验中没有完全排除蛋白质的作用
A: Excuse me, are you Sam?
B: Yes, I am.____
A: My name is Bob.
B:____
A: Nice to meet you, too.____
B: No, I'm not.____ Where are you from?
A: I'm from Beijing.____
B: Thank you.
A. Welcome to Beijing.
B. Are you from England?
C. What's your name?
D. I'm from America.
E. Nice to meet you.