计算:
-8m2-|4m-2m2-(3m-m2-7)-8|。
解:-7m2-m+1。
通过进行现场试验或试验室试验等理化试验手段,取得数据,分析判断质量情况的检验方法,称为( )。
A.目测法 B.试验法 C.量测法 D.分析法
Your vessel is equipped with totally enclosed lifeboats. Which statement is TRUE when the boat is enveloped in flames?().
A.The ventilators will automatically close by the action of fusible links
B.The motor takes its air supply from outside the lifeboat to prevent asphyxiation of the crew
C.A water spray system to cool the outside of the boat is operated by a high-volume manual pump
D.An air tank will provide about ten minutes of air for the survivors and the engine