Before anyone thinks about making a judgement on the kids at this school remember that EVERY school has kids who give answers like these. If they didn't, then every school would have EVERY child getting 70% or more for EACH subject.
When asked about why scientists think the dinosaurs became extinct, the correct answer should be that, currently, the most popular theory is that there was a massive asteroid which impacted the earth, sending up clouds of dust and ash that obscured the light. This, in turn, caused both a decrease in photosynthesis (and hence a decrease in plant growth and plant life), a decrease in the amount of oxygen present in the atmosphere, and an increase in the amount of carbon dioxide present. The fact that the dust obscured the light also resulted in a global cooling and an ice age. Because the dinosaurs are ectothermic (i.e. control their body temperature using the heat from the environment), they were unable to cope with the decreased temperature. This combined with lack of food and lack of oxygen, caused many species to become extinct.
Here are some of the more humorous incorrect answers I got:
- The dinosaurs were killed by a bomb that went off. [OK then.... sure. Why not? That makes sense, right?]
- The asteroid blocked out the sun's light before it hit the earth because it was so big [which means it must have been much bigger than the moon], and so when it hit the earth the dinosaurs were too weak to withstand the blast so they fell over and died. [I guess they're assuming that all the dinosaurs were in the Gulf of Mexico at the same time....]
- A glacier hadn't burnt up completely and when it hit the earth it whipped out the species. [glaciers? glaciers that whipped? I think I want to live in your world.]
- As [the archaeologists] found more remains they started thinking there should have been a more recent occurrence of extinction because they kept finding more fossils that ages well, but not that far back. [Um.... yeeees. Did you read your answer back to yourself? How did this sound in your head when you were writing it?]
- It could be possible [i.e. that the dinosaurs went extinct] but there are no proven facts to back the theory up. [Whatever your personal belief about creation and mass extinctions, kiddo, you still have to be able to explain the Alvarez-asteroid theory....]
- An asteroid decided one day that it did not like the asteroid belt, because it was being made fun of by its friends for being smaller than them, and then it went on a trip to have a closer look at the sun as it was moving it noticed a planet was going to be in its way, it tried to change its course, but the sun's gravity would not let it and it decided that it wanted to commit suicide any way and kill whomever was on that planet. The end. [Notice that that first bit is all one sentence! Phew! Great little bit of creative writing there.]