1. What is the lecture mainly about?
A. The length of time required to produce sedimentary rocks
B. The role of climate conditions in the creation of sedimentary rocks
C. Some processes that produced a specific group of rock formations
D. Some unique geologic features found in canyons in the United States
2. According to the professor, what is one characteristic that frost wedging and runoff share?
A. Neither occurs in a desert.
B. Neither is a frequent event.
C. Both are weathering processes
D. Both are seasonal phenomena
3. Why does the professor show a picture of a slot canyon?
A. To give students a sense of the size of a typical slot canyon
B. To show students one of the places they will visit on their field trip
C. To illustrate how many sediment layers are visible in a typical slot canyon
D. To show how much slot canyons can vary based on local climate conditions
4. What is the professor’ s attitude toward students exploring Bryce Canyon on their own?
A. He worries that students may not know to take appropriate precautions if they go by themselves.
B. He suspects that many students will not go on their own if such a trip requires them to get up early.
C. He hopes that the class field trip will motivate students to visit Bryce Canyon on their own.
D. He believes that students learn more from individual exploration than they do from being in a group.
5. How is a hoodoo formed?
A. Runoff produces large gravel deposits
B. Air pollution leads to a buildup of limestone.
C. The roof of a rock window collapses
D. A flash flood washes away the base of a rock wall
6. According to the professor, what two factors explain why a hoodoo does not have a smooth shape? Click on 2 answers.
A. The presence of acid in rainwater
B. The temperature swings between the summer and the winter seasons
C. The composition of the hoodoo’s sedimentary layers
D. The location of the cracks created by frost wedging
答案：C D A A C AC