46. A) Not all of them are symptoms of dementia.
答案出处: There are pretty clear differences between signs of dementia and age-related memory loss.
47. C) Communication within our brain weakens.
答案出处: Changes in brain cells can affect communication between different regions of the brain.
48. A) Totally forgetting how to do one's daily routines.
答案出处: Forgetting how to operate a familiar object like a microwave oven, or forgetting how to drive to the house of a friend you’ve visited many times before can also be signs of something going wrong.
49. C) Turn to a professional for assistance.
答案出处: Daffner suggests going to your doctor to check on medications, health problems and other issues that could be affecting memory.
50. D) Staying active both physically and mentally.
答案出处: And the best defense against memory loss is to try to prevent by building up your brain's cognitive reserve.
51. C) They all experienced terrible misfortunes.
52. B) The utmost comfort passengers could enjoy.
53. A) It was a mere piece of decoration.
54. D) The belief that they could never sink with a double-layer body.
55. A) She was used to carry troops.