Here are the sentences based on the given cues:

78. I am going to visit my friend after work this evening.

79. Residents and store owners have been concerned about the new mall for a few months.

80. What is Mum going to do this weekend?

81. You ought to go to the market to buy fish and vegetables.

82. People can do everything without help thanks to modern equipment these days.

83. How old was your brother or sister then?

84. Some people in the neighborhood are not happy with the changes.

85. It is difficult to learn two languages at the same time.