A:煤炭的大量燃烧
B:汽车尾气的大量排放
C:食品包装袋的随意丢弃
D:工厂废气的任意排放
对于函数fx)中任意的x1,x2x1≠x2有如下结论:①fx1·x2=fx1+fx2;②fx1+x2=fx1·fx2;③f-x1=1fx1;④fx1-1x1<0x1≠0;⑤fx1-fx2x1-x2>0.当fx=2x时,上述结论中正确结论的个数是( )
There are enough cups for each visitor to have _______.