11.Installing scrubbers in smokestacks and switching to cleaner-burning fuel are the two methods available to Northern Power for reducing harmful emissions from its plants. Scrubbers will reduce harmful emissions more than cleaner-burning fuels will. Therefore，by installing scrubbers， Northern Power will be doing the most that can be done to reduce harmful emissions from its plants.

　　Which of the following is an assumption on which the argument depends？

　　（A） Switching to cleaner-burning fuel will not be more expensive than installing scrubbers.

　　（B） Northern Power can choose from among various kinds of scrubbers，some of which are more effective than others.

　　（C） Northern Power is not necessarily committed to reducing harmful emissions from its plants.

　　（D） Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone.

　　（E） Aside from harmful emissions from the smoke-stacks of its plants， the activities of Northern Power do not cause significant air pollution.

　　12.In 1990 all of the people who applied for a job at Evco also applied for a job at Radeco，and Evco and Radeco each offered jobs to half of these applicants cants. Therefore，every one of these applicants must have been offered a job in 1990.

　　The argument above is based on which of the following assumptions about these job applicants？

　　（A）All of the applicants were very well qualified for a job at either Evco or Radeco.

　　（B） All of the applicants accepted a job at either Evco or Radeco.

　　（C） None of the applicants was offered a job by both Evco and Radeco.

　　（D） None of the applicants had applied for jobs at places other than Evco and Radeco.

　　（E） None of the applicants had perviously worked for either Evco or Radeco.