Answer:
The 4th sentence is punctuated correctly.
According to my dentist, I need to brush my teeth for at least two minutes.
The piont of initial perturbation. We need at lest three seismographic stations
Answer: The main reasons that so many more people died in Haiti (100,000+) than in Chile (523) is that the buildings in Haiti were not built to withstand earthquakes and therefore collapsed whereas buildings in Chile are built to a strict earthquake resistance code.
