Which of the following is true of plastic trash that ends up in ocean garbage patches?

“Superweeds” are weeds that _____________

  The mass number of an atom is the _______

  A general rule says that after _____half-lives, radioactive material has decayed enough to be rendered safe.

What was a drawback to implementing modern farming methods in China and India?

Which of the following does NOT have environmental costs associated with it?

  What is true of large hydroelectric dams?

You are shopping for a newer-model smartphone. At the store, the salesperson tells you if you trade in your old phone, you can receive a discount on the newer model. This is an example of:

Which of the following is NOT a way to reduce indoor air pollution?

Tropical rainforests have thin, acidic soils, yet they contain dense vegetation and high biodiversity. How can these tropical forests have poor soil and support such a diverse array of life?