氟氯烷氢
A．硬脂醇220gB．十二烷基硫酸钠15gC．白凡士林250gD．羟苯乙酯0.25gE．丙二醇120g水加至1000g
参考答案：E
I had a little trouble ______English grammar. [ ]
A. to leam
B. learning
C. learned
D. learn
空载扰动试验所选出的调节系数主要是满足机组空载运行的稳定性。
