Read the passage below. Look for clues about its text structure. Swimming in the ocean is different from swimming in a pool. The ocean is so huge there is no way to see where it ends. It is full of waves, so the water is often rocky. Swimming can be difficult and even dangerous for some people. A pool is smaller than the ocean so it is possible to see all sides of almost every pool. The water is calm and those who are not good swimmers can usually still have a good time in a pool. What words suggest a compare and contrast text structure? Select one: a. different from b. can be c. full of d. dangerous for