21．Lin Dan's recent book, which is based on his experience as____ Olympic badminton gold winner, became ．bestseller in China
A．/;a B．an; the C．/;the D．an; a
22．－Have decided what to do next year?
－Yes． ．I will study abroad in Harvard University or Yale University．
A．If anything B．If necessary C．If ever D．If possible
