21£®——Could I use your English dictionary for a few moments?

    —— ________£®I’m not using it myself.

       A£®Come on           B£®It depends           C£®Go ahead           D£®That’s great

22£®Read the passage and correct the mistakes, ______.£®

A£®if not              B£®if any                C£®if ever              D£®if never

23£®People have planted a lot of trees and grass in order to ____ wind and sand in the desert.

A£®hold down       B£®hold up        C£®hold back      D£®hold out