题目

若，，则在方向上的投影是________ 答案：【答案】【解析】直接代在方向上的投影公式即得解.由题得在方向上的投影为.故答案为：-2根据所给首字母或中文意思写出单词的适当形式，每空一个。 61. The college, founded centuries ago, was completely d___________ in the terrible earthquake.  62. You are required to pay for your p___________ before you leave the supermarket.  63. G__________, the whole city was covered by sandstorm from AD200 to AD400. 64. Last night I went to the bookshop and the shopkeeper r_______________ a new book to me.    65. Our school made it a rule that the students should attend the flag-raising c           with their school uniform （校服）every Monday morning. 66. The newly-built park will be              （有利的） to the people living there.   67. Mr. Fat is an              （有智力的）man because he always can solve the problems when in difficulty.  68. He was back in the office,              （更新）the work schedule on the computer. 69. She had difficulty in               （决定/确定）where to hang the picture in her new flat. 70. Stratford police refuse to make              （评论）on whether anyone has been arrested.