Answer: 1. and, 2. for, 3. is.
Explanation: A conjunction is a linguistic form that has the main function of joining together two phrases or clauses. In the first sentence, the conjunction is "and" it joins the words "mother" and "father" (the function of "and" is to express addition). In the second sentences the conjunction is "for" it helps to explain the reason of the award "for writing". In the third sentence we have to fill in the blank with the correct verb, for the other verb present in the sentence: "grows" we can infer that the sentence is written in present form, and the verb that makes more sense is "to be", so the correct answer is: mr. Kallas is the only farmer left who grows these kinds of tomatoes.
