Sixty-five million years the dinosaurs all suddenly disappeared trom the earth ago, Until recently, scientists did not understand why this happened, but then, in Mexico they discovered a huge circle more than 100 milesi609 kilometers wide, This circle was caused by some very. large object, probably a meteor, that hit the earth and caused changes in the earth's climate a sea levels. These changes may have
helped the dinosaurs live longer
b. been necessary for the dinosaurs.
killed the dinosaurs in Mexico
d. been disastrous for the dinosaurs.