21. —Oh, must you leave? Having dinner with you was such ______ fun.
—Thanks, anyway. I have to make ______ early start tomorrow morning.
A. 不填; an B. a; an C. 不填; the D. the; an
22. —Can I help you, sir?
—These shoes are too ______ and I need a bigger pair.
A. loose B. delicate C. exotic D. tight
23. Experts at the conference agreed that such a product with environmentally friendly technology is ______.
A. worth being promoted B. worthy promoting
C. worthy of promoting
D. worthy of being promoted
