用英语说：“既然你已经在学校学习，何不努力地去学呢？”

Why not study hard since you are already here in school?

1楼的翻译是错的，2，3楼的中式英语的痕迹太明显，5楼的属于一个一个字翻的，恐怕外国人看了会不知所云

since you've already studied in school,why don't you try your hard to learn?

Since you have already in school, why not hard to learn it

Why not study hard since you have studied in the school?

2楼3楼答案一样，都应该把句子末尾的in the school中的the去掉才对，1楼感觉上不应该那样翻译

Why not study hard since you have studied in the school