题目内容：
3. We can conclude from this passage that ______.A. the sea resources have largely been used up
B. the sea, in the broad sense, has not yet been developed
C. the problems that prevent us from using the food, minerals, and energy sources of the sea have already been solved.
D. by the year 2000 , the technology will be good enough to exploit all the sea resources
参考答案：