Activity 4. Sean and Find Directions: The questions below are all actual, they can be answered to merely weaning the passage below looking for clue words from the questions Sixty-five million years ago the Cretaceous period ended Many believe it under abruptly. Sources vary widely regarding the changes that occurred, but on average state that between 50 anul 76% of all plant and arumal e perished at this time of the arumals, only amphibians and mammals survived Fossilised dinosaur remains discovered in the mid-1800s. Since then the reason for their derde has intrigued both scientists and loy people. The most reliable restable hypothesis concerning their extinction was proposed by Alvarea arud Alvaren in 1980. Walter Alvares, a geologist, un collecting sedimentary samples near Cubbio, naty, working as part of a team measuring iridium Not commonly found in Earth's crust and mantle, tratum has been regularly detected in scientific samples from other parts of the solar system, in other words, the team was searching for cosmic dust. Aluaren discovered again, sources vary between 1 and 2 centimeters thick at the point believed to mark the boundary between the Cretaceous and Tertiary periods This layer had an Iridium content 30 times higher than its surrounding layers 1. Who proposed the most recent testable hypothesis concerning the extinction of the dinosaurs? A. a geologist C. Popular Science Magazine B. Alvarez and Alvarez D. National Geographic Magazine. 2. What is iridium? A cosmic dust C. fossilized dinosaur remains B common Earth element D. an element found only on Venus 3. According to the passage, which of the following is widely believed of the Cretaceous period? A. Between 50 and 75% of all plant and animal life appeared at that time. B. Everyone agrees what happened at the time. C. It was the period before the Tertiary period. D. It ended suddenly. E. It is the current geological period. 4. During Tertiary period, when were the fossilized dinosaur remains first discovered? C. in the inid - 1800s A. doing the pre-Cretaceous period D. during the post - Cretaceous period B. during the Cretaceous period 5. Who was the geologist collecting sedimentary sardples near Gubbio, Italy? C. Walter Iridium A. Walter Alvarez B Alvarez Gubbio D. Wensley Italy​