Question

か

(C)に当てはまる単語を選び形を変えて入れる問題です。入る単語はlookで、回答はlooksでしたがなぜlookedがダメなのかが分かりません。理由を教えて欲しいです。

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times
ir way in the early morning hours.
Another concern has to do with the cost implications of delaying school start
- an ever-present issue in the age of increasingly tight school budgets, and
decreasing tax revenues.
The move could lead to a range of initial up-front
costs, with budget-watchers worried most ( 2 ) costs/associated with changing
bus schedules and additional lighting for athletic fields because after-school
activities would be pushed later in the day.
However, our recently released research for the RAND Corporation ( B )
that delaying school start times to 8:30 a.m. could actually result in significant
economic statewide benefits that would be realized within a matter of years.
Over the span of about a decade, the United States could stand to make
financial gains of around $83 billion if teenagers were able to get more sleep. In
California alone the financial gains would be just over $10 billion. Within even
two years, most states would break even in terms of the initial costs of the move
versus the economic benefits.
These gains are based on a macroeconomic model that ( C ) at two key
effects of better-rested teens: improved academic performance and reduced motor
vehicle crashes.
In terms of academic performance, research published ( 3 ) the apt title

Answer 1

ごぼん

このlookは〜〜に注目した、という意味だと思います。よく休息（睡眠）のとれたティーンたちの二つのキーエフェクトに注目したミクロ経済のモデル、という訳になります。この文において、注目されたのは二つのキーエフェクトで、行為をしたのはミクロ経済のモデルですので、looksになります。looked は過去分詞として使いたいならthatが不要またはthat is となるはずで、過去形として使いなら、大きな文のthese gains are と時制を合わせる必要があるのでここでは不適です。