51. Listen __________ please. (care)
 
52. We’re __________ that our environment is spoiled. (disappoint)
 
53. Our boys play __________ today. (disappoint)
 
54. We’re worried about the __________ here. (pollute)
 
55. This river is extremely __________. (pollute)
 
56. A __________ faucet may waste 500 liters of water a month. (drip)
 
57. Her appearance is __________ today. (need)
 
58. Farm __________ are always exported. (produce)
 
59. This plant’s __________ is high, so it attracts a lot of investment. (produce)
 
60. The __________ of this machine requires the latest techniques. (produce)