<span>The angiosperms became more common during the cretaceous period. The Cretaceous period occurred almost 144 million years ago and it followed the Jurassic period. </span>
Answer:
They were not justified bc they were only tested on animals
Explanation:
Pure water is very close to a pH of 7. The Great Salt Lake (from what I've read about) can range from 8.2 to 7.7 in different areas. Saliva is between 6.5 and 7.5. And ammonia has a pH of 11.
So the items that have a pH between 5 and 8 are pure water, saliva, and possibly the Great Salt Lake.
Electricity could be discovered using batteries based on zinc or lead, but without copper wiring it would remain little more than a scientific curiosity. Electric motors and generators require large amount of wiring, so they are impossible to build on large scale in this world