题干
补全下面的短文。
The children are in the ____park．They are very busy．John is____leaves．Zhang Peng is watching the ____．And Chen Jie is watching the bird．Mike is catching butterflies．Sarah is____pictures．Amy is picking up leaves．Wu Yifan is____．
答案(点此获取答案解析）
nature,collecting,fish,drawing,singing
I)一旦被人体吸入，可能会引发甲状腺疾病。下列说法正确的是
为等差数列，
，
，则
等于