依据《中华人民共和国环境保护法》，开发利用自然资源，应当合理开发，（），保障生态安全，依法制定有关生态保护和恢复治理方案并予以实施。

A.保护生态系统多样性

B.保护物种多样性

C.保护基因多样性

D.保护生物多样性

For many years, people （）electric cars. However, making them has been more difficult that predicted.

A. had dreamed of

B. have dreamed of

C. dreamed of

D. dream of