Kids who live in northern U. S. states are used to having class canceled every now and then because of snow. But on Monday, a number of schools across the Northeast closed their doors _____16_____ a different reason: dangerously cold outdoor temperatures. Throughout the region, temperatures _____17_____ below zero. Schools canceled classes or delayed openings to protect students from the _____18_____ . The wind chill made it feel _____19_____ cold as 25 to 30 degrees below zero. The weathermen issued warnings about the _____20_____ of staying outside in the cold for too long. The cold was expected to last until Thursday. 【題組】17 (A) fell (B) made (C) raised (D) touched