她选了低速挡小心翼翼地沿小径下行。She selected a low gear and started down the track carefully.眼前有一条清晰可辨的小径通向山谷。A clearly defined track now leads down to the valley.从克拉斯特到牛顿有一条两英里的海滨小径。There is a 2 mile coastal walk from Craster to Newto...
There are doubts about the usefulness of these tests.这些试验是否有用，人们有所保留。I was persuaded of the usefulness of his new device.我相信了他的新装置的实用性.The index adds appreciably to the usefulness of the book.索引明显地增加了这本书的实用价值....