21．Our efforts resulted ________failure. I think I'm also responsible ________ it.
A．in；to B．from；to C．in；for D．from；for
22．________ her email，I wrote her another one，telling her what I wanted her to do.
A．Having not received B．Not having received C．Not receiving D．Receiving not
23．The government is ________graduates to work in the places where conditions are hard.
A．insisting on B．appealing to C．approaching to D．deciding on
