The growth of home schooling is due to several factors EXCEPT______.
A. tutors
B. parents
C. course materials
D. tutoring systems
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在证明细胞分化是基因选择性表达结果的实验中，分别用成红细胞中珠蛋白基因、输卵管细胞的卵清蛋白基因以及胰岛细胞的胰岛素基因分别作探针进行杂交。需要运用到下列哪种杂交方法？()
A. Southem杂交
B. Northem杂交
C. Western杂交
D. Southern杂交和Northern杂交
According to the passage, the law of diminishing marginal utility______.
A. is explained by income and substitution effects
B. explains why the additional units yield less utility
C. shows that the additional units yield less satisfaction
D. reflects the consumer's desire to get the cheapest buy
People' different attitudes towards death show that______.
A. people in other countries don't have a great health-care system as Americans do
B. Americans rely too much on their health-care system even to challenge death
C. Americans are optimistic
D. palliative care works wonders in Americans
细胞内蛋白质含量最高的细胞器是()。
A. 高尔复合基体
B. 溶酶体
C. 线粒体
D. 过氧化物酶体
E. 细胞核
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