Question

SAT语法题求助！

16. The sculptures of Michael Kapetan function as sundials, kept time by casting shadows that show the path of the Sun. No error
为什么这里的kept要改为keeping，S+V+O,Ved.....应该也可以的吧
21.Seventy-five percent of the apples A.(sold in) New York City come from the West Coast or overseas, B.(even though) New York State produces C.(more than enough) apples D.(to meet) the city's needs. E.No error
答案是E但是这里的A为什么要用过去式，后面不都是现在时吗
27．Langston Hughes may be best known for his poetry, but included among his many published works are a sizable collection of short stories. No error
答案是D， 为什么呢？？这句话不明白啊
29. The Bactrian camel is well adapted to the extreme climate of its native Mongolia, having thick fur and underwool that keeps it warm in winter {and also} insulate against summer heat. 问and also不是不能连用的吗，为什么这里是对的呢？
谢谢谢谢！感激不尽！！！！！！！！！！！

Answer 1

16.keep time与主语构成主动关系，所以应该用-ing形式。

21.sold in是语态不是时态，跟现在时没有关系。用作apples的后置定语，并与apples构成被动。

27Langston Hughes因其诗歌而著名，但是他所出门的诸多作品中，有许多短篇小说。（译得比较直，这样有助于理解。）

29感觉and also会出现在口语里。书面中是缀余。and作为连词已经有“并且”的意思，不需要also这个表达同样意思的副词了。