Ensure that the frame is securely fixed to the ground with bolts.确保用螺栓把框架牢牢地固定在地面上。Fit hinge bolts to give extra support to the door lock.安上铰链插销，让门锁更牢靠。He's more concerned about the nuts and bolts of location work.他...
The oxygen reacts vigorously with the impurity in the iron.氧气与铁中的杂质发生剧烈的化学反应.This impurity must be purged away after death.这种污秽应该在死后加以净化.The impurity of supposedly pure subcellular fractions is a constant threat to the p...