(4) 下線部 that の内容
【元の問題文】
次の英文は、中学生のケン（Ken）とALTのマルタン先生（Ms. Martin）の対話の一部である。また、図はケンのクラスが1週間の給食の食べ残しをはかった結果である。
Ms. Martin:Ken, what are you studying?
Ken:I'm studying *food loss in school lunch. Our class *measured the food we left last week.
Ms. Martin:1 did your class leave last week?
Ken:We left 51 kilograms in one week. Look at this graph. We left the most vegetables, and we left as much soup as meat. The amount of vegetables we left was 3 that of rice.
Ms. Martin:That's a lot. Why do students leave vegetables?
Ken:Some students don't like them, and the *portions are too big for some students.
Ms. Martin:In France, some schools let students choose a small or large portion.
Ken:That's interesting.
Ms. Martin:I also read about schools in Finland. There, students *serve lunch by themselves, so they take only the amount they can eat.
Ken:In our school, the same amount of food is put on every plate. If students serve themselves, they won't leave much food. I think we can do that in our school, too.
Ms. Martin:Good. But you should also think about the people behind your lunch.
Ken:What do you mean?
Ms. Martin:Farmers grew the vegetables, and cooks made the lunch for you. If you remember that, you may want to eat more.
Ken:You're right. I didn't think about the people who made our lunch.
Ms. Martin:What will you do next?
Ken:I'll ask my teacher if students can 5.
Ms. Martin:That's a good first step.
〔注〕*food loss＝食品ロス *measure＝〜をはかる *portion＝1人分の量 *serve＝（料理を）盛りつける left＝leaveの過去形 put＝putの過去形 made＝makeの過去形 read＝readの過去形 did＝doの過去形 was＝beの過去形
(4) 下線部の that が指す内容として最も適切なものを選びなさい。
選択肢を選ぶ（並べかえは「答え合わせ」を押す）と、すぐ正解と解説が出る。間違えたら解説を読んで次へ進む。
① 同じ文の中を見る
下線部を含む文の前で、ケンは If students serve themselves, they won't leave much food. と言っています。
ケンが学校でもできると考えたことは？