A:初中物理教科书的长度约为26dm
B:中学生正常步行的速度约为4km/h
C:人感觉舒适的气温约为40°C
D:1s内人的脉搏约为72次
—Yes, he was the first Chinese writer ________ won the prize for children's literature.
火药武器广泛使用实战出现于( )