The most common construction woods are Douglas fir, hemlock, spruce, pine, and some cedar.最常用的木料是道格拉斯冷杉, 铁杉, 云杉, 松木以及其他一些杉木.Here is a beech by the side of a hemlock, with three pines at hand.这儿有株山毛榉和一株铁杉长在一起,旁边还有三株松树.Hem...
Excessive energy is also required to achieve appropriate pressures and vacuums.还需要额外的能量来造成所需的压力和真空.My personal theory is that needs and desires create mental vacuums.我个人的理论是,需求和欲望制造了思想真空.Both vacuums and pure oxygen cond...