请教白勇中的一题

xxxyyyzzz1

7．If a single strain
of plant is used for a given crop over a wide area, a practice fostered by
modern seed-marketing methods, it increases the
likelihood that the impact of a single crop disease or pest will be disastrous.

    （A）If a single strain of plant
is used for a given crop over a wide area，a practice
fostered by modern seed-marketing methods，it

    （B）If a single strain of plant
is used for a given crop over a wide area, as is fostered by modern
seed-marketing methods, it

    （C）A practice fostered by
modern seed-marketing methods, a single strain of plant used for a given crop
over a wide area

    （D）A single strain of plant
used for a given crop over a wide area, a practice fostered by modern
seed-marketing methods，

    （E）The use of a single strain
of plant for a given crop over a wide area, a practice fostered by modern
seed-marketing methods,

答案E

答案说D插入语的用法不对，想请教一下，插入语怎么用呢？

能分析下CDE直接的区别和CD的缺陷吗？

谢谢啦～～

[此贴子已经被作者于2009-4-7 15:31:49编辑过]

xxxyyyzzz1

请大家指教啊

谢谢咯

enrique1313

use 对应practice-作同位语

strain错！