【C20】A．thoseB．thatC．oneD．ones

【C20】A．whichB．thatC．whetherD．when

This hospital is______provides the best services in the city.A．whatB．thatC．one whichD．the

Its such a difficult problem______no one can work it out.A．asB．thatC．soD．this

【C20】A．theseB．thoseC．the oneD．that

【C20】A．certainB．anyC．someD．one

Many workers were organized to clear away_______ remained of the World Trade Center.A.thoseB.thatC.