An environmental friendly phosphorus - free degreaser is obtained by orthogonal test.通过正交试验得到一种以表面活性剂为主、辅以助剂的环保无磷脱脂剂.Remove oil and grease, etc. with a suitable detergent or degreaser.用适当的清洁剂和脱脂剂除去油脂.This machine is main...
He sat behind a desk laboriously writing with an Army issue pen.他坐在书桌后吃力地写着，用的是一支部队发的钢笔。She is tracing laboriously now.她正在费力地写.She is laboriously copying out an old manuscript.她正在费劲地抄出一份旧的手稿。...