Cepheid variable stars are stars whose brightness changes at regular periods.造父变星是一种光线按规律周期发生变化的恒星.His first great discovery was made when he recognized a Cepheid variable star.他的首次重大发现产生于他认识了一颗造父变星的时候....
I've grown so lonesome, thinking of you.想起你，我觉得非常寂寞。He was finding the river lonesome.他发现这条河很偏僻。feel lonesome寂寞I felt so lonesome after he left.他离开后我感到非常孤单。...
Policemen preserve [ maintain ] order in the streets.警察在街上维持 秩序.Police were sent for to maintain order.请了警察来维持秩序.The police maintain order in the city, help prevent crime, apprehends lawbreakers and directs traffic.警察维持城...
在粗糙不平的水泥窗台上有一条细细的发光水印。A thin, glistening thread of moisture ran along the rough concrete sill.这里又有一座高低不平的城堡建在悬崖绝壁之上。Here another rugged castle crowns the cliffs and crags.床垫是否高低不平并且下陷？Is the mattress lumpy and saggy?...