Could be a graduated cylinder. Hope this helps :)
Nitrogen-fixing bacteria change nitrogen into a form of soluble nitrates that plants can use ...the air is 80% nitrogen but it is in N2 form which plants cannot use
1 is most likely mutation
There's been a lot of bad news for polar bears recently. In 2007, for example, scientists reported that if global warming continues unabated, the population could drop two-thirds by 2050.
