36、 Every field of chemistry different chemical reactions．
A．holds
B．consists
C．composes
D．involves


37、 In Beijing there are many sites of historical interest__________
A．to be visited
B．of visiting
C．to visit
D．when visiting


38、 It is no easy job to be a teacher． One has to be extremely patient __________ the students．
A．At
B．about
C．on
D．with


39、 So heavy __________that we were prevented from going out．
A．the rain was
B．is the rain
C．was the rain
D．would the rain be


40、 __________ we can get rid of pollution is still a big problem．
A．Whether
B．If
C．that
D．what


41、 We have to __________ many difficulties in the course of social reforms．
A．cope with
B．keep with
C．come up with
D．catch up with


42、 Americans eat__________ vegetables per person today as they did in 1910．
A．more than twice
B．as twice as many
C．twice as many as
D．more than twice as many


43、 Such __________the case, there are no grounds to justify your complaints．
A．is
B．was
C．is being
D．being


44、 The politician urged that all citizens__________ to the polls on election day.
A．had gone
B．went
C．must go
D．go


45、 You can't afford to let the situation get worse． You must take __________to put it fight．
A．decisions
B．directions
C．sides
D．steps