The three-dimensional vector r , which has positive components, has magnitude 1 and makes angles of with each of the unit vectors i and j . The angle between r and the unit vector k is ° .
【简答题】page 60 Complete the following sentences by translating the Chinese into English, using as as a relative pronoun. 用 as 把下列句子中的中文翻译成英文 Such conservative people ( 如你所描述的 ) ______ are rare nowadays. At t...