Why must nations sometimes work together to solve environmental problems

Alexa is preparing for a presentation by creating note cards identifying keywords that describe various features of each type of plate boundary. which words apply to all three of the convergent boundaries?

An uncomfortable feeling in the ears when descending in an airplane is caused by changes in air pressure on the: a. inner ear b. middle ear c. eardrum d. hammer/anvil

What do genes contain the code for?