What range of numbers would you expect on the ph scale for an acid.

What percentage of the earth's water is available for use by living things?

When your working with the passage-based reading questions on the psat do all of the following except. a)make sure you read each question throughly. b) try to answer each question before you look at the answers. c) plan to spend most of your time reading the passage. d) make sure your answer choice is the most correct number me

Which statements are true for invasive species? 1. they always stabilize an ecosystem. 2. they’re always successful in adjusting to a new habitat. 3. they often compete with the native species for resources. 4. they have the ability to displace the native species. 5. they’re always pests.