问题
选择题
| — John sings so well. Has he ever been trained? — No. He learns all by himself. He ______ goes to any training class. |
A. usually B. often C. never D. even |
答案
答案：C
搜题请搜索小程序“爱下问搜题”
| — John sings so well. Has he ever been trained? — No. He learns all by himself. He ______ goes to any training class. |
A. usually B. often C. never D. even |
答案：C
PCl3+Cl2，2NO2
N2O4，均为气态）后，PCl5和NO2的转化率均为a%。保持温度、容积不变，向两个容器中分别再充入 1 mol PCl5和1 moLNO2，又达到平衡时PCl5和NO2的转化率分别为b%和 c%，则下列关系中正确的是[ ]