A:3﹣甲基﹣4﹣乙基戊烷
B:2,3﹣二甲基戊烷
C:3,4,4﹣三甲基已烷
D:3,5﹣二甲基已烷
The company won the bid for the project by saying that it would do the cleaning up afterwards ________.
下列物质中:①空气②酱油③食醋④汞⑤水⑥矿泉水⑦氧气⑧氢气⑨二氧化碳⑩铁。纯净物的是____,混合物的是____。
下列各数中,比﹣1小的数是( )