语法填空（共10小题；每小题1.5分，满分15分）。

I felt upset when I 1__________ (tell) that I would have to leave the company. In order to find 2__________ new job to support the family, I read almost all the newspapers 3__________ set down almost all the telephone numbers in ads 4__________ my notebook and tried to call almost all the companies that needed new clerks. Not until I 5__________ (find) a job in a small town near Townsville did I calm down. My new boss, Mr. Brown, was one of my schoolmates 6__________ I was getting along well with at school. Both of us were 7__________(excite) to see each other and we spent the whole afternoon 8__________(talk) about things and persons that we remembered at school. He asked me to give 9__________ some advice on how to enlarge his present business and he was 10_________(entire) happy about my advice.     

按一定的贴现率将方案在整个实施或作用期内的效益及成本均贴现，所得的效益现值与成本现值之比是指（）。

A.静态效益-成本比

B.效益-成本比

C.动态效益-成本比

D.成本-效益比