honestly for me its between 2 and 3
D)...... Hope it helps, Have a nice day:)
Answer:
only helium makes balloons go up so the answer is helium
Explanation:
1. Their large ears help dissipate excess body heat on hot days in the desert.
2. The fennec fox seems to be the only carnivore living in the Sahara Desert able to survive without free water. Their kidneys are adapted to restrict water loss, their extensive burrowing may cause the formation of dew, which can then be consumed, and they will receive moisture from the food that they eat.
3. Their burrowing and nocturnal lifestyle helps restrict water loss.
4. Their thick fur helps insulate them from the cold desert nights.
5. Their sandy fur helps to reflect heat, and also provides excellent camouflage.
6. Fennec foxes also have thick fur on the soles of their feet, which insulate against the hot sand of the desert. This extra fur on the soles of their feet also affords them excellent traction in the loose sand.
Darwin lived in a time where natural selection was a strange theory among scientists and researchers. This was especially true when other researcher Lamarck argued that organisms passed on helpful traits to their offspring, that they magically could form a new trait to adapt to their environment and then pass it onto their offspring. For example, if a giraffe was too short to reach food, it would grow a larger neck in its lifetime and then pass that trait onto its offspring. Darwin argued that, through the process of survival of the fittest, that short giraffe would die off and never receive the chance to pass on its shortness to future populations. Thus, taller giraffes would survive— they can reach food, shorter giraffes can’t— and the short genes would disappear. The fact that Darwin was introducing a new theory that nobody was used to at the time was peculiar, so he had few people on his side until long after his observations.
Another problem Darwin had was the lack of technology. To travel, Darwin would have to use boats to reach far away places, and of course, this took time.
The final problem Darwin had was the extra time it took for evolution, a process that can take up to millions of years. Evolution didn’t occur over night— it took time for Darwin to conduct experiments, observe, conduct them again, come to a conclusion, and so on.
Hope this helped a little!