一下3题出自大全补充“其它”部分。没有很清晰的思路，请高手指点。

22. Recently, evidence was found near Lake Baringo in Kenya that may have been the earliest known use of fire by ancestors of Homo sapiens.

(A) Recently, evidence was found near Lake Baringo in Kenya that may have been

(B) Recently found near Lake Baringo in Kenya was evidence of what may have been

(C) Evidence that was recently found near Lake baringo in Kenya may have been

(D) Near Lake Baringo in Kenya, evidence was recently found that may be

(E) Found recently near Lake baringo in Kenya is evidence that may be what was

31. Sales of United States manufactured goods to nonindustrialized countries rose to $167 billion in 1992, which is 14 percent more than the previous year and largely offsets weak demand from Europe and Japan.

A) which is 14 percent more than the previous year

B) which is 14 percent higher than it was the previous year

C) 14 percent higher than the previous year’s figure

D) an amount that is 14 percent more than the previous year was

E) an amount that is 14 percent higher than the previous year’s figure

33. Sound can travel through water for enormous distances, prevented from dissipating its acoustic energy as a result of boundaries in the ocean created by water layers of different temperatures and densities.

A) Prevented from dissipating its acoustic energy as a result of

B) Prevented from having its acoustic energy dissipated by

C) its acoustic energy prevented from dissipating by

D) its acoustic energy prevented from being dissipated as a result of

E) preventing its acoustic energy from dissipating by

－－－－－－－－－－－－－－－－－－－－－－－－－

答案BEC

22 题B里“what”指代什么？

31题C错在哪里？

33题C里“ its acoustic energy prevented from dissipating by。。。”在句中做什么成分？

谢谢！

22 题B里“what”指代什么？

what 引导从句， 相当于名词作定语。等同于the thing that

31题C错在哪里？

在句中作的成分不明显。

33题C里“ its acoustic energy prevented from dissipating by。。。”在句中做什么成分？

做独立主格成分。