Explanation

How Earthquakes Happen

Earthquake is one of the most destroying natural disasters. Unluckily it often happens in several regions. Recently a horrible earthquake has shaken West Sumatra. It has brought great damages. Why did it occur? Do you know how an earthquake happens?

Earthquakes are usually caused when rock underground suddenly breaks along a fault. This sudden release of energy causes the seismic waves. It make the ground shake. When two blocks of rock or two plates are rubbing against each other, they stick a little. They don't just slide smoothly. The rocks are still pushing against each other, but not moving. After a while, the rocks break because of all the pressure that's built up. When the rocks break, the earthquake occurs.

During the earthquake and afterward, the plates or blocks of rock start moving, and they continue to move until they get stuck again. The spot underground where the rock breaks is called the focus of the earthquake. The place right above the focus is called the epicenter of the earthquake.
( source: http://bos-sulap.blogspot.com )

Discussion

National Exam in Pros and Cons?

National exam becomes the hot topic in most of discussions. Though the Supreme Court has rejected an appeal by the go-vernment on the organization of the national exams, the controversy over whether it is necessary to maintain the national exams (UN) has continued. Some debates include the primary questions such as; does the quality of Indonesia education depend on the national exam?, will the quality of the Indonesian education system worsen without natipnal exam?

People, who support the national exam explain that the quality of the Indonesia education system will drop without the national exam, so they try to defend the current system.

Hoever there are people who disagree with the opinion. Those who against this national exam kept in our high school education say that it doesn't need the national exams because the quality of education does not just depend on the national exam. Further, the national exam only measures a small portion of students' competence in specific subjects, and does not measure students' competences throughout the semester.

In fact, the national examination can still be useful as an instrument to evaluate or detect the level of students' cognitive competence in several subjects, on a national scale.

( source: http://bos-sulap.blogspot.com )