51. I really appreciate ____ time to relax with you on this nice island．(have)

having　

50. Do let your mother know all the truth．She appears _____everything．(tell)

to have been told

49. ___such heavy pollution already，it may now be too late to clean up the river．(suffer)

Having suffered

48. With a lot of difficult problems ____，the newly-elected president is having a hard time．(settle)

to settle　

47. When ____，the museum will be open to the public next year．(complete)

completed

46. In some parts of London，missing a bus means ____for another hour．(wait)

waiting

55. Prices of daily goods ____through a computer can be lower than store prices．(buy)

bought

44. ____to sunlight for too much time will do harm to one’s skin．(expose)

Being exposed

43. Don’t use words，expressions，or phrases ____only to people with specific knowledge．(know)

known

42. Though ____money，his parents managed to send him to university．(1ack)

1acking