请根据所给首字母或中文提示，写出单词在句中的正确形式。每空只能填一词，将单词完整地写在答题卡上。（每小题1分，共10分）

81. We should protect the animals in d _________.

82. Susan was so careless that she made many m_________ in the test.

83. Can you give me some a_________? My English is so poor.

84. Singing English songs can i_________ our English.

85. My son likes eating hamburgers. He says they are very d_________.  

86. It’s _________ （礼貌的） to wait for everyone to put some food on their plates.

87. The _________（气温）will fall below zero.

88. They didn't have _________（足够的）food to eat and they felt hungry.

89. Plants and animals can't live _________（没有）air or water.

90. Don’t be _________（紧张的）. It’s easy.