题目

 I first went to hear a live rock concert when I was eight years old. My brother and his friends were all ___36____ of a heavy metal group called Black Wednesday. When they ___37____ that Black Wednesday were going to perform at our local theatre, they all bought ____38___ for performance. However, at the last minute, one of the friends couldn’t go, so my brother __39_____ me the ticket. I was really ___40____!     I remember the buzz (嘈杂声) of excitement inside the theatre as we all found our __41____ . After a few minutes, the lights went down and everybody became ___42____如图所示，O点为杠杆的支点，请画出力F的力臂，并用字母L表示；