Sodium ethylate was used as catalyst in Baker - Venkataraman of cyclization, and all factors were studied.环合反应采用乙醇钠作为Baker-Venkataraman重排反应的催化剂, 研究了影响反应的各个因素....
农场雇用了一名拖拉机手和两名杂工。The farm employed a tractor driver and two general labourers.如果我们很在乎钱, 我们最好不做杂工.If we were serious about money, we'd quit being hired hands.杂工非常辛苦, 收入却很低.Odd - job workers work very hard , but don&#...
He entreats a bowstring to be fastened on the arm, must not fasten on the neck.他请求把绞索系在手臂上, 千万不要系在脖子上.An arrow fitted to the bowstring cannot avoid being discharged.箭在弦上,不得不发.It is hard to bull back the bowstring.要拉开弓弦挺难...