He started to learn English when he was 12 years old.(保持原句意思）

题目

He started to learn English when he was 12 years old.(保持原句意思）
He__start to learn English __he was 12 years old
2.Without rain,the living things will be all dead.(保持原句意思)
If___ ___ no rain ,the living things will be all dead

答案

很高兴能够在这里回答你的问题：
He started to learn English when he was 12 years old.(保持原句意思）
He　（didn't）start to learn English (untill) he was 12 years old
not untill 句型
2.Without rain,the living things will be all dead.(保持原句意思)
If　（there is）no rain ,the living things will be all dead