Cyclopentanone ethylene ketal was synthesized with I _ 2 as catalyst.以单质碘为催化剂合成了环戊酮乙二缩酮.The effects of reactant mole ratio , catalyst dosage , microwave irradiationtimeyield of cyclohexanone glycol ketal were investigate...
太多的学校在争夺太少的生源。There are too many schools chasing too few pupils.太多的冷水和太少的肥皂了, 这么多年.Too much cold water, too little soap, too many years.太少的钱抵达指定的目标或有助于持久的发展.Too little has reached the intended target or contributed to la...
Every year more adventurers sailed west from Spain.每年有更多的冒险家从西班牙向西航行.When we think of adventurers, many of us conjure up images of larger-than-life characters trekking to the North Pole.一想到探险者，我们很多人脑海中浮现的便是长途跋涉前往北极的非凡人物形...