野餐时石头和树桩都充当了椅子.Rocks and stumps supplied the place of chairs at the picnic.我磕到了树桩上,胫部擦破了皮.I barked my shin on a tree stump.他把树桩用作桌子.He used the stump as a table....
Steven killed the bird with his pocketknife.史蒂文用随身带的小刀杀死了这只小鸟.I got a really good pocketknife for $ 10.我花十美元买了一把非常好的折叠刀.Now, use your pocketknife to touch the mica and see what will happen.现在你用小刀去触及岩石中的云母,看看会产生什么现象....