1.eightieth八十岁生日.特殊变形去y加ies
2.farther 扔的比我远.比较级.
3.playing
只有三种情况只用start to do sth.
1.start本身用-ing
He is just starting to write the letter.
2.主语是物不是人
The ice started to melt.
3.其后的动词与想法感情有关
She started to understand it.
所以这里用start doing
4.relaxing 根据句子此处填名词.relax变为动名词.
5.saying 此位固定变法.翻为谚语.