完形填空
阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案。
Health Insurance（保险）
Most Americans are responsible for their own medical costs.These can be extremely high if a person gets very（51）or has an accident.So people buy a health insurance plan to make sure these costs will be（52）.
Most American colleges and universities have（53）health centers.There may even be a teaching hospital that can treat more serious（54）.
Some medical services may be included in the cost of attending a school.But health insurance is usually needed for extra services.（55）most full-time college students must have insurance.
Students may already be protected under their family's health plan.If not,many colleges offer（56）own plans.
The University of Michigan will be our example.Students pay a health service fee.Then there is no extra charge when they are treated for minor（57）problems at the University Health Center.But the school wants students to have health insurance to pay（58）other services.
The insurance plan（59）by the university costs about one thousand seven hundred dollars a year.Such health insurance（60）generally pay for hospital services,emergency room care and visits to doctors.They（61）do not pay for care of the teeth.And they usually do not pay for treatment of medical conditions that existed（62）the student arrived at school.
International students at the University of Michigan have two（63）.They can buy the university health plan.Or they can（64）private insurance that is approved by the university.
The school also offers a special International Student Insurance Plan.This pays for most of the services offered（65）the University Health Center that are not included in the health service fee.
51.A.rich B.poor C.sick D.old
52.A.laid B.paid C.made D.said
53.A.family B.woman C.man D.student
54.A.services B.problems C.needs D.solutions
55.A.So B.But C.Yet D.Though
56.A.our B.its C.his D.their
57.A.personal B.medical C.learning D.travel
58.A.at B.on C.for D.in
59.A.taken B.taught C.offered D.accepted
60.A.dollars B.centers C.plans D.schools
61.A.usually B.luckily C.suddenly D.carelessly
62.A.after B.if C.before D.since
63.A.choices B.conditions C.terms D.cases
64.A.have B.reject C.invest D.borrow
65.A.on B.for C.to D.by
