77. Using the techniques employed by genetic engineering, a new species of microorganism has been developed by laboratory scientists to aid in cleaning up oil spills by digesting the oil.

(A) Using the techniques employed by genetic engineering, a new species of microorganism has been developed by laboratory scientists to

(B) Using the techniques employed by genetic engineering, a new species of microorganism that was developed by laboratory scientists will

(C) Using the techniques of genetic engineering laboratory scientists have developed a new species of microorganism to

(D) Employing the techniques of genetic engineering there has been a development by laboratory scientists of a new species of microorganism that will（C）

(E) Employing the techniques of genetic engineering, a new species of microorganism that was developed by laboratory scientists will

C中的using the techniques of genetic engineering,这里不应该是有个逗号的么?

E为什么错?

个人理解，应该是有一个逗号，但即使是没有也应该选C。

E项

Employing the techniques of genetic engineering, a new species of microorganism that was developed by laboratory scientists will aid in cleaning up oil spills by digesting the oil.

a new species of microorganism 无法Employ the techniques of genetic engineering。

E) Employing the techniques of genetic engineering, a new species of microorganism that was developed by laboratory scientists will

我认为employ 在这里应该可以用，它和 use 不一样，后者只能指人用，前者主语可以是物。我们也有类似说法， 这款手机采用3g技术。

但是后面的太累赘，语法不顺畅，这才是原因吧。