gather的现在进行时为：gathering...

combine的现在进行时为：combining...

bestialize的现在进行时为：bestializing...

较轻的推进器采用液态氢, 较重的采用自燃推进剂.The lighter version used liquid hydrogen, the heavier used hypergolic propellants.这个工厂为弹道导弹生产推进剂。The factory produces propellant for ballistic missiles.挤压 式 发动机对推进剂中溶解的气体特别敏感.Pressure - fed engine...

imprint的现在进行时为：imprinting...

act的现在进行时为：acting...

molest的现在进行时为：molesting...

mesmerize的现在进行时为：mesmerizing...

esterify的现在进行时为：esterifying...

auction的现在进行时为：auctioning...

daydream的现在进行时为：daydreaming...

resurrect的现在进行时为：resurrecting...

throat的现在进行时为：throating...

burgle的现在进行时为：burgling...

handle的现在进行时为：handling...

recompense的现在进行时为：recompensing...

fuss的现在进行时为：fussing...

admonish的现在进行时为：admonishing...

flicker的现在进行时为：flickering...

instate的现在进行时为：instating...

silt的现在进行时为：silting...

introspect的现在进行时为：introspecting...

kiss的现在进行时为：kissing...

whinge的现在进行时为：whingeing...

withdraw的现在进行时为：withdrawing...

elect的现在进行时为：electing...

advocate的现在进行时为：advocating...

reform的现在进行时为：reforming...

dictate的现在进行时为：dictating...

clerk的现在进行时为：clerking...