Which of the earth’s spheres is composed of all the water on the planet, including oceans, seas, and rivers? a. the hydrosphere b. the atmosphere c. the biosphere d. the lithosphere

Venezuela’s economy relies most heavily on which of the followingvenezuela’s economy relies most heavily on which of the following? a. oil reserves in places such as the eastern llanos b. cattle ranching in the grasslands c. fertile farmland in the andean highlands d. coffee plantations in mountainous areas

The us and canadian governments are doing all of the following to combat environmental problems except a. encouraging the use of public transportation b. enacting clean water policies c. requiring emissions testing d. limiting animal populations in some regions

Read the article titled "castro resigns." why did the us impose trade sanctions against cuba in 1962?