birthday celebration during assembly?

I don't like drawing economy graphs, "keluk" to be more exact! Especially the MC cutting through AC's lowest point and when I have to draw AVC. I dislike the AC a lot cause MC always have to cut AC's minimum point and AVC has to start from far and ends close to AC.
Yucks, it really takes me such a long time to get the intersection. I'm really lousy at these drawings!
I cannot be a architect..haha

BTW:
AC = Average Cost (Kos purata)
AVC= Average Variable Cost (Kos Berubah Purata)
MC = Marginal Cost (Kos Sut)

Onto a diff topic:
Ya, today's assembly was quite weird...
You know what? We celebrated the Head prefect's (Ismail Daud) birthday today...Whoa, this is the first time I've heard about a student's birthday celebrated in assembly!
It was all the Principle's (Pn Hamidah) idea and Pn Hamidah also bought a secret recipe cake for Ismail Daud.

OK, now onto another subject: HISTORY
My history teacher(Pn Maimon) gives us unexpected written "test" when she feels like it...quite rare la. This year twice already. Each time she gives us a "test", she doesn't care about it in the end--> she doesn't want it!
So, I feel really discouraged in putting effort to memorize within the short period of time for this "test" as she doesn't really care about the end result!
Some people feel relieved that she doesn't collect these "test"...But I feel like it's a waste of time, ink, paper and effort...I put effort in memorizing in those 5 minutes she gave us to refresh our minds before doing the "test"...I feel sad la... ;C