下列说法中用离子方程式或电离方程式表达正确的是（      ）

    11-year-old Jerome is good1running. He usually wins all of the races at Serpentine Primary School in Australia. However, after giving up2 a recent school race, the boy has won hearts of3 people. In the race, the kind boy ran back to walk with his good friend Seth and let him4the finishing line first.

    10-year-old Seth was born with cerebral palsy (脑瘫). Since he moved to the school last year, he5a lot of problems at school. Luckily, Jerome6to help him by the teachers with things like going to the toilet and showing him around. The two boys soon became good friends

    Because of his7Seth has a big head, some students laugh at his appearance. Jerome usually has a word with Tom, asking them 8that. Seth's father can't thank Jerome enough for looking after his son. "He is9 good kid." The two boys' story has spread quickly after Jerome's mother Susan shared it on social media. "These boys are champions10they didn't win," said the proud mother.

给出下列命题：

①定义在R上的函数f（x）满足f（2）＞f（1），则f（x）一定不是R上的减函数；

②用反证法证明命题“若实数a，b，满足a²+b²=0，则a，b都为0”时，“假设命题的结论不成立”的叙述是“假设a，b都不为0”．

③把函数y=sin（2x+ $\frac{\pi }{3}$ ）的图象向右平移 $\frac{\pi }{6}$ 个单位长度，所得到的图象的函数解析式为y=sin2x．

④“a=0”是“函数f（x）=x³+ax²（x∈R）为奇函数”的充分不必要条件．

其中所有正确命题的序号为____．