2000年7月1日或以后建造的船舶禁止使用()为灭火剂的灭火系统。
A、卤代烃1211
B、卤代烃1301
C、卤代烃2402
D、全氟化碳
参考答案:A, B, C, D
— Haven't I told you that you should be home earlier?
— Yes, but I home earlier than I usually do. [ ]
A. was coming
B. will come
C. came
D. had come
制备空胶囊壳时一般要加甘油和羧甲基纤维素,二者的作用为()
A.增塑
B.芳香矫味
C.着色
D.遮光
E.防腐