You should associate with people who you believe are trustworthy.
信頼に足りると思う人と付き合うべきです。
Will this much food do for a week's camping?
これだけの量の食料で一週間のキャンプに足りるでしょうか。
An income adequate for one's needs.
必要を満たすに足りる収入。
Will this cover the holiday expenses?
休み中の費用は、これで足りるかな。
But so that we may not cause offense, go to the lake and throw out your line. Take the first fish you catch; open its mouth and you will find a four-drachma coin. Take it and give it to them for my tax and yours.