他能一连几个小时呆在实验室里。
Whereas purposeful men could make their way across a narrow bridge, the slow diffusion of plant and animals would require an avenue as a continent and available for ages at a stretch.有目的的人可以通过一座狭窄的桥,而植物和动物的缓慢扩散则需要一条像大陆一样的道路,而且需要很长时间才能使用。
Today I really swam to my heart's content. I did 3,000 metres at a stretch.今天我一口气游了三千米,真过瘾。