e been silent the whole day, man!— I’m feeling ______ blue today. I didn’t do well inthe speech contest.

Mike, these are my friends,Dale and Eric. —-___________

下列各句中加点的成语使用恰当的一项是(　　)

The research on the new flu virus vaccine ischallenging and demanding Who do you think can do the job—____ my students have a try

_________ running after success, we have a lot of other interesting things to do in our lives.