at the biginning 与 in the beginning 有何区别?

at the biginning 与 in the beginning 有何区别? make an introduction后用什么介词at the biginning of the meeting ,the headmaster made an intorduction _______himself.A.to B.of C.foe D.at 1.There is a thing that is the first to pity and the last to help 2.I am the biginning of sorrow,and the end of sickness3.You cannot express happiness without me; yet I am in the midst of crosses I am at the open I enjoyed____(I) at the party. at the library与in the library-When do your classes end?-They end at noon.Then I have a job at the library.请问:这里的at the library可以换为in the library吗? wish to do 与 want to 为什么 I wish to see the manager .= I want to see the manager.I wish the manager to be informed at once .=I want the manager to be informed at once . I was________(surprise)at the news. I love the way you smile at I was ______(surprise)at the news. I have finished the essay at last. I am( )at the ( )(surprise)news. I look at you across the I text my friend at the shop, look at the girls.i like I'm at the top of my I was (a ) at the bad news I stayed at home the w___ day.