根据句子意思和所给首字母或中文提示，在标有题号的横线上写出一个英语单词的完整、正确形式，使句意通顺。
81. Calculate what p______ of your income you spend on food.
82. Even slight rent increases would cause considerable h_____.
83. As the wages were low, there were few a______ for the post.
84. Scientists are hoping for a b_____ in the search for a cure for cancer.
85. Your ticket is v_____ for travel at anytime of the day.
86. Radio is an important communication _______(媒介) in many countries.
87. Team members will be selected according to strict ______.(标准)
88. I want to get a new passport but I don’t know the ______. (程序)
89. At the ______(最初的) stage of the project not everyone had access to a computer.
90. It is useful to have a ________(附近) supermarket.
