OG10语法268题及GWD22语法总结四十九
48. The golden crab of the Gulf of Mexico has not been fished commercially in great numbers, primarily on account of living at great depths-- 2,500 to 3,000 feet down.
A. on account of living
B. on account of their living
C. because it lives
D. because of living
E. being they live
1．代词指代,数的同等：（一级拂拭B,E）
2.词法 : (because句子优选)：（二级拂拭A,D）
A. because +完整的句子
B. on account of / because of + n. ==》此处没有明白的限命名词的内涵
C. Because》on account of / because of
because, which appears in C and E, is preferable here since because can introduce a complete subordinate clause explaining the reason why the golden crab has not been fished extensively
. C, which uses because and it as the singular subject of a clause, is the best choice.
(言下之意，主谓宾说的最清晰)
3.通俗现在式默示继续发作的毕竟和真理。