Official 50 Lec 4
Question 1 of 6
What is the lecture mainly about?

A.

Efforts to increase the production of petroleum and natural gas

B.

Problems associated with the refining of dead oil

C.

Recent improvements in methods used to locate petroleum

D.

Background information essential to understanding the petroleum industry

正确答案:D

显示答案
进入答题
00:00
00:00
隐藏原文

译文

精听文本