6. The Grand Canyon is . A. land surrounded by water
B. a dry, sandy area with no trees
C. a flat topped hill
D. a deep, narrow valley with steep sides

7. The large shapes of land that make up the earth are all called
.
A. peninsulas
B. landforms
C. waterways
D. mountains

Astudent pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. she then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. the student performs the experiment one more time but this time she stirs the mixture rapidly. the dependent variable in this experiment is: time for salt to dissolve speed of stirring amount of water mass of salt