Sound waves can't travel through
a. an elastic material.
b. a liquid.
c. a solid.
d. a vacuum.

Match the types of competition to their descriptions

What would happen if a plant could carry out photosynthesis, but not respiration? question 1 options: it would have no food. it would have too much water. it would be unable to capture the energy in sunlight. it could make food but not break it down for energy.

Which of the following was a social cost associated with the development of the internal combustion engine used in most cars? a. people were able to use their horses for new tasks. b. new jobs were created. c. blacksmiths needed to gain new skills to continue working. d. families were able to travel farther more easily.