I'll need to buy a large, strong, light backpack to carry my supplies of food and water.

我得买一个又大又牢而且很轻的旅行背包来装我的食物和饮用水。

youdao

I will need to buy a large backpack to carry my supplies of food and water.

我需要买一个大的旅行背包来背负我的食物和水。

youdao

I don't have enough money to buy the new backpack.

我没有足够的钱来买新背包。

youdao

So I think I'm going to buy a new backpack.

所以我在考虑换一个新的双肩包。

I need 实战 - SpeakingMax英语口语达人

But so inept was Hassoun, he bought a backpack, walkie-talkies and some batteries agents asked him to buy and the FBI then incorporated it into the dud bomb fashioned at its lab in Quantico, Va.

NPR: Would-Be Chicago Backpack Bomber Gets 23 Years