防止羊毛缩绒的方法有（）.
A.碱减量处理法
B.拉伸细化法
C.氧化法
D.氢氧化钠膨胀
参考答案：C
— When did the computer crash?
— This morning, while I ________ the reading materials downloaded from some websites.[ ]
A. have sorted
B. was sorting
C. am sorting
D. had sorted
调节三羧酸循环运转最主要的酶是
A．丙酮酸脱氢酶B．柠檬酸合酶C．苹果酸脱氢酶D．延胡索酸酶E．异柠檬酸脱氢酶
