已知函数,给出下列结论: (1)若对任意,且,都有,则为R上的减函数; (2)若为R上的偶函数,且在内是减函数,(-2)=0,则>0解集为(-2,2); (3)若为R上的奇函数,则也是R上的奇函数; (4)t为常数,若对任意的,都有则关于对称。 其中所有正确的结论序号为 。 答案: (1),(3) Spoken English slightly
differs from country to country.For instance, in some parts of the US the “r” sounds at the end of
the words______.
A.is dropped B.have dropped
C.has dropped D.are dropped