Answer:
nos, le
Explanation:
The words in brackets in front of the sentence are what allows us to choose the word. For the first sentence, it says a nosotros. The sentence then says the waiter gave __ (to someone) good food. Since it says nosotros, we know that it's nos a pronouns meaning us. The second sentence says, a el. Therefore, we can figure out that the pronoun will be le, which means the clients gave him a good tip.
