21. — Oh , must you ? Stay a bit longer. It has been such ______ fun having you here.
— Thanks. I’ve got______ early start tomorrow morning.
A. a; an B./; the C./; an D. the ;/
22. Don’t you think it essential that every resident of Nanjing __________ spare no effort to make contributions to Nanjing 2014 Youth Olympic Games?
A．should B．will C．shall D．would
