Choose the correct answer：
1.Dr.Wong has an excellent reputation (______) a heart specialist.
A.to B.as C.be D.in
2.In order to meet the deadline for submitting the final design of the art work,we need to be more (______)
A.effect B.efficiency C.efficient D.sufficient
3.The BBC World Service (______) throughout the world.
A.receives B.broadcasts C.outcasts D.censors
4.From the helicopter the police had a bird’s eye (______) of the accident.
A.from the view B.view C.to view D.viewed
5.There are (______) classes and activities offered during the summer by the government.
A.various B.variety C.variation D.vary
6.You are (______) from tax if you are a student.
A.obliged B.liable C.exempt D.optional
7.The (______) of the hard drive is 500GB.
A.capacity B.capable C.loading D.ability
8.Many of the problems were caused by a (______) in communications.
A.outset B.breakdown C.feedback D.outbreak