?突然大笑起来

Burst out laughing; burst into tears.突然大笑起来；突然哭起来 Bursting apart, as some seed pods when ripe.爆裂的，如一些荚果成熟时 .

?突然笑了起来

... burn up烧掉，烧毁；烧起来，旺起来；(使)发怒 burst into突然开始；闯入，非法进入 burst out laughing突然笑了起来 burst out突发，突然发作；喊出来 ...