穿过地理梯度, 莱文斯预料有分布区不重叠的小种或近群种.Across geographic gradients, Levins expects allopatric races or coenospecies exist.航空磁梯度仪在六十年代中期交付使用.The airborne magnetic gradiometer came into use in the middle 1960 s.这说明水动力条件具有很明显的位能梯度.Thi...
过来吧，好多老朋友都在这儿。Come on over, we've got lots of the old gang here.我们在村里偶然碰见了一些老朋友。We ran across some old friends in the village.你总不会对老朋友见死不救吧？You wouldn't leave an old friend in the lurch, surely?...
伊萨的白色沙滩帽在刺眼的阳光下闪闪发亮。Issa's white beach hat gleamed in the harsh lights.这艘船停靠在细沙滩上。The ship has come to rest on the fine sand.附近有一片白色沙滩，是沐日光浴的绝佳场所。Nearby there is a stretch of white sand beach perfect for sunbathing....
In twenty years of mar-riage he has only taken two proper vacations.结婚二十年里，他只像样地度过两次假。Don't allow a minor irritation in the workplace to mar your ambitions.不要让工作中的一点烦心事打击了你的雄心抱负。It was not the custom for elderly peo...