But when I entered junior high school and had the military training.

后来，我升初中的时候，参加了军训。

youdao

But when I entered high school we have to solve a lot of math problems.

但当我上了高中我们必须解决很多问题。

youdao

But when I entered high school we have to solve a lot of math problems. We have to use a calculator. It makes my homework easier.

但上了高中后我们要解答许多数学题，也就不得不借助计算器了，做家庭作业也变得轻松了。

youdao

But it was his words: "Ladies and gentleman, I am a police officer, " when he first entered the carriage, that calmed those who he evacuated and let them know someone had come to help.

BBC: INSP STEPHEN MINGAY MBE, BRITISH TRANSPORT POLICE