21. Shangri-la is really ____ beauty, which is _____ home to many kinds of rare birds and animals.
A. a; a B. /；the C. a; / D./; /
22 It may not rain; but you’d better take an umbrella ______.
A. in return B. in need C. in case D. in fact
23. If we have a strong will, we can overcome any difficulty ______ it is.
A. what B. how C. whatever D. however
