这台发动机类似目前的单作用煤气和重油发动机.This engine resembled present single - acting gas and oil engines.重油报价为每桶17美元.The heavy oil was quoted at $ 17 per barrel.这种重油会妨碍机器的运转.That heavy oil will clog up the machinery, ie prevent it from w...
The flower structure in one tree was different, enforcing cleistogamy.同一株树上的花结构不同, 因而闭花受精是强制实现的.This trait is called cleistogamy and occurs naturally in some plants.这种特性称为闭花受精;一些植物会自然发生闭花受精....