Maybe you should use the extra time in class to practice up on your English skills
As for the L96A1 topic, it should kill in one shot unless they have a heavy vest on. Other possibilities could be that...
- You're an insanely far distance from them, which will usually result in 1 or 2hp remaining.
- They're lagging badly (seriously I've had times where I've shot the guy 3 or more times, saw blood and heard the impact... they survived.)
- If you have the S1 attached it will occassionally leave them with very low health.