He is vacuuming a rug in the sitting room.他在起居室里用吸尘器打扫地毯.L am vacuuming the floor now and have several shirts to iron.我正在用真空吸尘器清理地板,还有好几件衬衫要熨.But a wide - open floor adds only a few seconds the vacuuming chore.但是,广泛的开放式购...
The internuclear distances in molecules can be measured in many ways.分子中的核间距,可以用很多方法测定它.The hypothetical electron smeart must exert a net attractive Hellmann - Feynman force to counterbalance the internuclear repulsion.假...
教师的忠告启发我深思.The teacher's advice gave me plenty of food for thought.他脸上露出深思的表情.He had a thoughtful look on his face.她深思地凝视着远方.She stared thoughtfully into the distance....