TOEFL IBT Reading Practice Test 21 Solution & Explanation
1. B The passage does not state that an unbroken prairie now extends from the western mountains to the eastern forest. All of the other answers are given: ...temperatures can vary widely from very hot in summer to bitter cold in winter; The wetlands were soon surrounded by fluttering waves of grasses: shortgrass, mixed grass, and tall grass; An important feature of the northern Great Plains grasslands is the presence of millions of glacial depressions that are now small ponds known as prairie potholes. (1.2)