A:80°C的水正在沸腾
B:温度达到水的沸点100°C,而不沸腾
C:沥青加热到一定温度时才能熔解
D:温度升高到0°C的冰而不熔解
John: What do you do on Sundays?
Tom: I read books and watch TV. What do you do on Sundays?
John: I do my homework . What about you, Mary?
Mary: I clean my room and watch TV.
John: You're helpful.
已知△ABC中,A(7,8),B(3,5),C(4,3),M,N是AB,AC的中点,D是BC的中点,MN与AD交于点F,求DF→.
大兴安岭——太行山——巫山——雪峰山一线是我国 ( )