163. Found throughout Central and South America, sloths hang from trees by long rubbery limbs and sleep fifteen hours a day, moving infrequently enough that two species of algae grow on its coat and between its toes.

1. sloths hang from trees by long rubbery limbs and sleep fifteen hours a day, moving infrequently enough

2. sloths hang from trees by long rubbery limbs, they sleep fifteen hours a day, and with such infrequent movements

3. sloths use their long rubbery limbs to hang from trees, sleep fifteen hours a day, and move so infrequently

4. the sloth hangs from trees by its long rubbery limbs, sleeping fifteen hours a day and moving so infrequently

5. the sloth hangs from trees by its long rubbery limbs, sleeps fifteen hours a day, and it moves infrequently enough

D, the best choice, correctly subordinates sleeping and moving to hangs while using the idiomatically correct phrasing so (infrequently) that.... The pronoun its shows clearly that the limbs belong to the sloth, not the trees. Choice A illogically coordinates hang and sleep and, like E, uses the unidiomatic expression infrequently enough that. B creates an awkward and nonparallel series: sloths hang ..., they sleep ..., and with.... C creates a confusing and absurd image with use their... limbs to hang ..., sleep ..., and move .... A, B, and C all mistakenly use the plural sloths, which does not agree , with its coat and... its toes. E wrongly coordinates hangs and sleeps and violates parallelism by inserting it before moves to create a new independent clause.

如果按照标准答案的理解选D当然是没有问题的the sloth hangs from trees by its long rubbery limbs, sleeping fifteen hours a day and moving so infrequently

但是我不能理解，如果用并列结构来考虑的话就应该是：the sloth hangs from trees by its long rubbery limbs, sleeps fifteen hours a day and moves so infrequently这样的有错吗？我一开始拿到题目，第一感觉就是这么想的，跟og的想法不一样。不知道为什么这样错了？

 虽然说的有道理，但是你无法在选项中找到你所说的这种，语法的选择是优选比

较的结果，也即5个里选最好的，不是填空。另一方面，本题中如果如你所言hangs,

sleeps和moves是并列关系就意味着三个动作彼此独立，改变的A的意思，其实句子想

要表达的是hangs的同时sleeping或moving. 而你的那种理解可以suppose为：hangs，

躺在树枝上sleeps，用飞行的方式moves。