第一节 单词拼写（每空只填一个单词，注意其正确形式。共5题，每题1分）
66. He is sure to come unless he has some u________(紧急的) work to do at home.
67. Take a positive attitude towards study and be a ________ in class, and you’ll surely make great progress in English.
68. Only warm-hearted and responsible university students can be admitted as v________（志愿者）.
