--I'd like to invite you to a concert this evening0 - 离问题结束还有 14 天 23 小时.--Thank you ,but _____I'll be free ,I'm not sure at the moment .1.when 2.while 3.whenever 4.whether
问题描述：
--I'd like to invite you to a concert this evening
0 - 离问题结束还有 14 天 23 小时
.--Thank you ,but _____I'll be free ,I'm not sure at the moment .
1.when
2.while
3.whenever
4.whether
答
4