where were you at supper time I _for you to join me.a have been waiting b.was waiting
问题描述：
where were you at supper time I _for you to join me.a have been waiting b.was waiting
答
B
你晚饭时间上哪儿了?（说明已经过了晚饭时间）所以后面一句话不能用have been waiting,因为have been waiting表示现在一直还在等,was waiting 表示当时我在等.
明白了么?