2017年12月英语四级阅读答案：试卷一仔细阅读1（沪江网校版）

　　答案

　　46. D) In what way it can be beneficial.

　　47. C) She got some idea from previous studies on birds and dolphins.

　　48. A) She monitored the brain activity of participants sleeping in a new environment.

　　49. C) She exposed her participants to two different stimuli.

　　50. B) They tended to perceive irregular beeps as a threat.