burst [ bɜ:st ] v. / n. 爆裂、飞散、爆发

1. burst into 闯入、（情绪）突然……起来

2. burst in on 突然出现、打扰

3. bury oneself in (doing) sth专心致力于（做）某事= be buried in (doing) sth

burn down / burn out / burn up 三者都有“烧毁”的意思。

burn down 强调火势减弱。

burn out 强调大火熄灭。

burn up 强调火烧起来。

· The room became colder as the fire burnt down.

随着炉火逐渐减弱，房间越来越冷。

· Finally, the fire was burnt out.

最终火被熄灭了。

· If you put on more coal, the fire will burn up.

如果你再多添点煤，炉火就会旺起来。

Q Don't ______ him while he's sleeping.

1. burst in on 2. break in 3. burst into