41、 Paper making in China __________ from there to North Africa and Europe.
A．sprang
B．spilled
C．carded
D．spread


42、 It has always been the __________of our firm to encourage workers to take part in social activities.
A．plan
B．campaign
C．procedure
D．policy


43、 The old gentleman never fails to help_______is in need of his help.
A．Who
B．Whoever
C．One
D．whomever


44、 The government placed __________ on the numbers of foreign cars that could be imported.
A．limitations
B．restraint
C．requirements
D．restrictions


45、All the reference books should be made________to the teachers and students in our university.
A．Concerned
B．available
C．related
D．flexible


46、 It is difficult for us to explain phenomena that we have little or __________direct knowledge.
A．no any
B．no
C．none
D．nothing


47、 No sooner had I closed the door than somebody started knocking __________it.
A．on
B．with
C．to
D．for


48、 As we know, physics __________the science of energy.
A．was
B．were
C．is
D．are


49、 These courses, if properly conducted, will________the minds of the students.
A．refresh
B．renew
C．Stimulate
D．encourage


50、The train __________ of the station right on time.
A．pulled
B．pulled down
C．pulled on
D．pulled out