例句與造句

1. They first tried steam at very high pressures, then a hot-air engine, and finally built and patented, in 1876 a very light steam boiler weighing from 39 to 44 lb . to the horse power, which appears to have been the prototype of some of the light boilers which have since been constructed.
2. It's difficult to find light boilers in a sentence. 用light boilers造句挺難的