21£®— How do you find _________ birthday party of the Blairs?

— I should say it was __________ complete failure£®

A£® a; a B£® the; a C£® a; / D£® the; /

22£® I really don’t know how to thank you , but for your help, I ______ my lost necklace£®

A.couldn’t have found    B.mustn’t have found     C.couldn’t find   D.wouldn’t find