Question

\please let the bell ring before mr. w. says anything,\ christopher whispered to himself. he stared at the wall clock as if his eyes could force it to move faster.\oh, and one more thing,\ said mr. wakowski, clapping to get everyones . christophers heart sank.homeworkattentionmoney

Explanation:

The context shows Mr. Wakowski clapping to gain the students' focus before speaking, which matches the meaning of the missing word. "Homework" and "money" do not fit the action of clapping to engage the group.

Answer:

attention