属真核生物染色质中DNA的三级结构的描述是
A．DNA的核小体结构B．tRNA的三叶草结构C．DNA双螺旋结构D．DNA的超螺旋结构
参考答案：A
My teacher asked me if I was worried about the test and I said "No". But _____ I was. [ ]
A. really
B. hardly
C. nearly
D. proudly
甲、乙两同学的质量之比是5：4，则他们的体重之比是______，若甲同学的体重是450N，则乙同学的体重为______N．
