Dr Meck wrote: "As is true with most animals, the wolf is an opportunist whilst the deer is one of the shyest ______ animals in existence."

单项选择题I regret ______ you that I can't go to Hangzhou for a visit next Sunday with you, because I've caught a bad cold.

单项选择题Our school singing group is going to give ______ performance next month; don't miss it.