As soon as the bell rang signaling the end of the class, the students rushed out of the room. This sentence is an example of -

• Complex sentence: 
- যে sentence এ একটি Principal clause এবং এক বা একাধিক Subordinate clause থাকে, তাকে Complex sentence বলে। 
- Complex sentence এর subordinate clause এর শুরুতে সাধারণত if, though, although, as, because, since, so that, that, until, till, unless, when, why, who, which, where, how, before, after, whether, while, as soon as, hardly had বসে।

• সুতরাং, নিয়মানুযায়ী -As soon as the bell rang signaling the end of the class, the students rushed out of the room. হচ্ছে complex sentence.