Which of the following is TRUE?____. A: If there is oxygen and fuel in an enclosed tank, there must be an explosion. B: Crankcase explosion is least likely to occur, because there is no air in crankcase. C: The droplets of lubricating oil splashing around in the crankcase is usually too large to start burning. D: The oil/air concentration in crankcase is usually too rich.

If the pressure is not _______ immediately, there may be an explosion.

燃油和氧气的混合物能引起爆炸。 A: A mixture of fuel and oxygen can cause an explosion. B: A mixture of fuel and hydrogen can cause an explosion. C: A mixture of fuel and nitrogen can cause an explosion.

Sheheard what ______ like a huge explosion.

One should not ___ the consequences of the world’s population explosion.

All of them, however, remained (live) ______ after the explosion.

Officials have not yet __________ what caused the accident or the explosion.

爆炸性（explosion）的局势

An explosion is a sudden increase in amount __________.

To distinguish sounds，students are encouraged to practice__________． A: minimal paim B: nasal explosion C: constant clusters D: incomplete explosion