The most likely reason the author included the class discussion with the tour guide was to
1) create a sense of unity despite colin's withdrawn attitude
2) provide a bit of action to a mostly internal discussion
3) teach a valuable lesson about participating in class discussions
4) use the students' comments and behavior to contrast with colin

Which evaluation category receives the highest rating? which evaluation category receives the lowest rating?

Which of these sentences would best express the main idea of a speech arguing that people should participate in a charity softball tournament? a) softball is a great way to get some much-needed exercise. eliminate b) the money raised by the tournament will local animal shelters. c) the tournament is a fun way to spend time with friends while a worthy cause. d) even if you don't have any softball experience, you can form a team and participate.

What is a mechanism by which organisms maintain homeostasis when the level of one substance influences the level of another substance or the activity of an organ.