然而，一定要注意，并非所有英美军官都执行命令。

It must be noted, however, that not all British and American officers carried out orders.

《柯林斯英汉双解大词典》

一定要注意先看清合约再交钱。

Make sure you read the contract before parting with any money.

《牛津词典》

一定要注意你饮酒和吸烟的习惯。

Do watch your drinking and smoking.

youdao

So it's a way of reminding you, I've got to be careful about the types of things that I put in.

因此我这是在提醒你，一定要对输入的东西的类型,多加注意。

麻省理工公开课 - 计算机科学及编程导论课程节选

Be careful.

一定要注意

耶鲁公开课 - 基础物理课程节选

Remember, you've got to keep track of the sign of acceleration, so if you're picking up speed towards the ground, a is negative, so it will be g plus a, but a is a negative number.

记住,一定要注意加速度的符号,所以当你加速下降的时候,a 是负的,还是 g 加上 a,但是 a 是负数

耶鲁公开课 - 基础物理课程节选