45. What made it necessary to build a road through the Glacier National Park?
(A) There were too many parks in Montana.
(B) The park was not sunny enough for visitors.
(C) The existing mountain roads were destroyed.
(D) More visitors were interested in going to the park.

41. Why do howler monkeys howl? (A) To claim their territory. (B) To check how popular they are. (C) To tell others they are going to leave. (D) To show friendliness to their neighbors.

42. Why did the howler monkeys in Belize howl less often? (A) They lived too close to each other. (B) There was enough food for all of them. (C) There were no other competitors around. (D) They were not used to the weather there.

43. Why do the keepers at the sanctuary use recorded howls? (A) To prevent the howler monkeys from getting homesick. (B) To help howler monkeys maintain their howling ability. (C) To trick the monkeys into the belief that there is plenty of space around. (D) To teach the monkeys how to make the loudest cries to scare people away.

44. According to the passage, which of the following is true about howler monkeys? (A) They howl most often at noon. (B) They originally came from Belize. (C) People can hear their howls three miles away. (D) Female monkeys howl to protect their babies.

46. How has the Going-to-the-Sun Road influenced the way people experience the Glacier National Park? (A) The scenery along the road is too beautiful for visitors to drive carefully. (B) It has become a marvelous experience for people to ride horses on this road. (C) The road has allowed people to see more of the park in a shorter period of time. (D) The transportation on the road was so difficult that few people could really enjoy the trip.

47. What does “an engineering feat” mean? (A) A big success in construction. (B) A magical building machine. (C) A great disaster for the travelers. (D) An enjoyable process for engineers.

48. What is special about the Waterton-Glacier International Peace Park? (A) It is where the glacier runs to the lake. (B) It is the first park funded by the whole world. (C) It is a special park built to protect wild animals. (D) It is composed of two parks located in two countries.

49. What kind of ice is ideal for sculpting? (A) Ice from ice hotels. (B) Ice from clean water. (C) Ice with lots of bubbles in it. (D) Ice weighing over 100 kilograms.

50. Why is ice sculpting difficult? (A) It is hard to control the size and shape of the ice. (B) The right theme for ice sculpting is not easy to find. (C) The appropriate tools are only available in some countries. (D) It is not easy to find the right kind of ice and work environment.

51. What is paragraph 3 mainly about? (A) The uses of ice sculptures. (B) The places where ice is sculpted. (C) The quality of ice sculptures. (D) The origin of ice sculpting parties.