题目

Some passengers complain that it usually _____ so much to buy to the ticket.  A.costs                B. takes                      C. spends                   D. spares   答案：A下列关于氧气用途的叙述错误的是A.潜水、医疗急救病人需要氧气B.液氧可做宇宙火箭的燃料C.氧炔焰用来焊接金属或切割金属D.氧气帮助燃料燃烧