45.
(A) mutual
(B) mutually
(C) convenient
(D) convenientlyIt is hard for people living fifty years ago to imagine how advanced the technology is today. 46 there would be electronic or even digital products invented. However, 47 some sci-fi movies, we might take a glimpse of the near future.In Iron Man, Jarvis, the mainframe of Tony Stark, 48 a user interface which directly responds to Tony. He doesn’t need to type in commands, 49 need to press any mouse button. By just 50 orders or simple gestures, he could make Jarvis respond quickly and appropriately. Another movie, Avatar, once again shows us the hologram, a special effect that has several times 51 audience 51 in sci-fi movies.52 these possible technologies in the future might bring us more colorful life, there are some problems we should face. One is that energy resources are 53 . To solve this problem, we should conserve existing resources 54 look for new ones to replace them. The idea of wind and solar power systems has been 55 in some places. Nevertheless, it still needs more people’s efforts to carry it out worldwide.