英文を日本語に訳して( )に入る語を選んでください
After the fine started, the number of late pickups promptly went up. Before long there were ( ) late pickups per week, more than double the original average. The incentive had plainly backfired.
So what was wrong with the incentive at the Israeli day-care centers? You have probably already guessed that the $3 fine was simply too small. For that price, a parent with one child could afford to be late every day and only pay an extra $60 each month just one-sixth of the base fee. As baby-sitting goes, that`s pretty cheap.
But there was another problem with the day-care center fine. For just a few dollars each day, parents could buy off their guilt. Furthermore, the small size of the fine sent a signal to the parents that late pickups weren`t such a big problem. If the day-care center suffers only $3 worth of pain for each late pickup, why bother to cut short the tennis game? Indeed, when the economists ended the $3 fine in the seventeenth week of their study, the number of late-arriving parents didn`t change. Now they could arrive late, pay no fine, and feel no guilt.
（）の中に入る適切な語句を選んでください。
(1)ten (2)fifteen (3)twenty (4)forty
