题目

Grandfather’s Clock In the dining room of my grandfather’s house stood a(n)   36   grandfather clock. Meals in that dining room were   37   for four generations to become one. And always that grandfather clock stood like a trusted family friend, watching over the laughter and story   38    and gentle kidding that were a part of our lives. Year after year, the clock   39  , a part of my memories, a part of my heart. Even more wonderful to me was my grandfather’s   40  . He wound that clock with a special key each day. That key was magic to me. It kept our family已知向量=（cos，sin）=（cos，sin），之间满足 （1）用k表示 （2）求      （12分）