_________(54)A.at B.inC.on D.for

The tide is, ______ , very high.A) at a timeB) at timesC) at the timeD) at other time

Several factors are ________ in the process of development.A at playB at onceC at home

__________[A] at first [B] at all [C] at large [D] at times

_________(62)A.off B.onC.up D.for

_________(60)A.normal B.necessaryC.domestic D.for

_________(58)A.by B.onC.in D.for