IV. Complete the sentences with the given words in their suitable forms.（用括号中所给单词的适当形式完成下列句子。每空格限填一词）
54. Don’t be afraid of making ___________. They help you learn. (mistake)
55. The medicine should be taken ________ a day, George. (two)
56. I plan to enter for a summer camp with a friend of ________. (me)
57. I’m not satisfied with the service here. I want to speak to the _______. (manage)
58. The boy moved ________ into the hall as the concert had already begun. (quite)
59. The soldier saved the boy from the flood with a piece of __________. (wooden)
60. Shops are not allowed to _________ cigarettes to anyone under the age of 18. (sale)
61. Many people enjoy reading e-books, but I _______ as it’s bad for the eyes. (like)