Item WE014004: Wind, water, and the growth of plant roots can wear away the solid rock of a valley.
Which of the following can break the rock layer that makes up the sides of a valley so that the valley becomes wider?
   
- Wind, water, and the roots of plants can break the rock layer.
- Water and wind can break the rock layer, but the roots of plants cannot.
- Water can break the rock layer, but wind and the roots of plants cannot.
- Neither wind, water, nor the roots of plants can break the rock layer.
- Distribution of Responses
 
																- Students Responding Correctly
| Group | Correct | Total | Percent | 
|---|---|---|---|
| Overall | 1303 | 2530 | 52% | 
| Grades | |||
| 6–8 | 750 | 1530 | 49% | 
| 9–12 | 550 | 990 | 56% | 
| Gender | |||
| Male | 629 | 1225 | 51% | 
| Female | 659 | 1262 | 52% | 
| Primary Language | |||
| English | 1165 | 2232 | 52% | 
| Other | 102 | 226 | 45% | 

