21．We were in ______ when we left that we forgot the airline tickets．
A．a rush so anxious B．a such anxious rush
C．so an anxious rush D．such an anxious rush
22．You will find this map of great ______ in helping you to get round Beijing ．
A．price B．cost C．value D．usefulness
23．It is not rare in_____ that people in ______ fifties are going to university for further education．
A．90s ; the B．the 90s; / C．90s; their D．the 90s ; their
24．----He was nearly drowned once ．
---- When was ______?
-----_____ was in 2000 _____he was in middle school ．
A．that; It ; when B．this ;This; that
C．that; This; when D．that; It ; that