6.She remains confident and ______ untroubled by our present problems.

　　A) indefinitely

　　B) infinitely

　　C) optimistically

　　D) seemingly

　　7.Fiber-optic cables can carry hundreds of telephone conversations ______.

　　A) simultaneously

　　B) spontaneously

　　C) homogeneously

　　D) contemporarily

　　8.The police were alerted that the escaped criminal might be in the ______.

　　A) vain

　　B) vicinity

　　C) court

　　D) jail

　　9.Whether you live to eat or eat to live, food is a major ______ in every family's budget.

　　A) nutrition

　　B) expenditure

　　C) routine

　　D) provision

　　10.Now a paper in Science argues that organic chemicals in the rock come mostly from ______ on earth rather than bacteria on Mars.

　　A) configuration

　　B) constitution

　　C) condemnation

　　D) contamination

　　11.There is much I enjoy about the changing seasons, but my favorite time is the ______from fall to winter.

　　A) transmission

　　B) transformation

　　C) transition

　　D) transfer

　　12.I think we need to see an investment ______ before we make an expensive mistake.

　　A) guide

　　B) entrepreneur

　　C) consultant

　　D) assessor