1. We’ll have a picnic in the park this Sunday ----- it rain

问题描述：

1. We’ll have a picnic in the park this Sunday _____ it rains or it’s very cold.
A. since B. if C. unless D. until 答案为什么是D?难道是标准答案变得“不标准”?

1个回答分类：英语 2014-10-20