问题
选择题
双链DNA分子中，一条链上的A占30％，则双链中C+T占 [ ]
A．50％
B．20％
C．30％
D．15％
答案
答案：A
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双链DNA分子中，一条链上的A占30％，则双链中C+T占 [ ]
A．50％
B．20％
C．30％
D．15％
答案：A
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| When your kids were six or seven, you sent them to school. Did you ever wonder what goes through a teacher's 1 as he or she tries to teach your kids? Did you ever wonder what the teacher 2 from you, the parents? Parents can be 3 or suspicious. They can be of great help to the teacher 4 be in need of help themselves. Some teachers think parents are too 5 on their children. Here is 6 one teacher puts it. "I usually have the 7 of parents coming in and 8 me how much they care about the kids' education and how they really 9 their kids. They tell me they stand and 10 them closely when they do their homework. Sometimes they 11 offer help with the kids' lessons as if they were teachers. They check their school work, and are too sensitive to 12 . They blame the kids on everything having to do 13 school. When a parent asks me how his or her kid is getting on in my class, my answer usually is' Well, you know, he is 14 a good kid. He is fine in my class. Maybe you don't have to be so 15 with your kid.'" Teachers want parents to know that they are professionals at 16 with children. They have 17 many children and even parents. Because of this, teachers can be 18 at educating children. Teachers are 19 that parents want their children to do well, but they know more about what children should be able to do at different ages and 20 . | |||
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