问答题 《复合题被拆开情况》 Imagine being able to print rocket engine parts, chocolate figurines, designer sunglasses, or even pizzas—just with pressing a single button. It may sound like something out of【M1】________science fiction, but it’ s increasing becoming a reality. Thanks to 3-D printing, 【M2】________companies are reimaging their long-term business plans. Invented in mid-1980s, 3-D printers create solid, three-dimensional objects【M3】________from various materials such as plastic, wax, wood, gold, or titanium. A major advantage of 3-D printing is that designs for objects can be easily changed. When designs were changed in traditional【M4】________manufacturing, the machinery that make the objects needs to be redesigned or upgraded, 【M5】________which can be very cost. But in the case of 3-D printers, only the software needs to be modified.【M6】________3-D printing is also better than traditional manufacturing because there is no wasted【M7】________material. With traditional manufacturing, some material is cut away from to create an object, 【M8】________but 3-D printing uses only which is necessary. Guided by software, a 3-D printer builds【M9】________an object one layer at a time, place material only where it needs to be. As a result, 【M10】________it can make complex objects less expensively.《问题》：【M4】