单项选择题
A.lower than B.higher than C.as much as D.the same as
Where an excessive level of contamination is detected a...
单项选择题Where an excessive level of contamination is detected an alarm is sounded and diverting valves are operatedThe discharging liquid is then passed to （）.
A.overboard B.a bilge well C.a slop tank D.a hot well
For the intermediate condition, thermostats must be cor...
单项选择题For the intermediate condition, thermostats must be correctly set （）.
A.by trial and error B.by and large C.automatically D.very easily
Most air conditioning units have （） for adjusting the r...
单项选择题Most air conditioning units have （） for adjusting the ratio of recirculated fresh airCare must be taken not to reduce the fresh air so that stuffiness or smells arise.
A.catch plates B.dampers C.regulating valves D.fans
