题目

在什么样的环境条件下种子才能萌发呢？以下是某小组同学在“探究种子萌发的环境条件”的实验记录。 实验装置 绿豆数 温度 水 发芽情况 甲 20粒 25℃ 无 种子不萌发 乙 20粒 25℃ 适量 种子萌发 丙 20粒 低温 适量 种子不萌发 请分析回答下列问题。 （1） 如果选甲装置和乙装置进行对照，提出的探究问题是？ （2） 如果选乙装置和丙装置进行对照，实验的变量                                My first performance in front of an audience was coming up soon.     I tried as hard as I could to remain calm, but my heart was racing. I stared down at my sweat-covered, shaking hands.     I looked up again at the audience, realizing that these were real people. They were not just my mum and dad, who would say, “Good job!” even if I messed up the entire piece.     What if I had the wrong music? What if I played the wrong notes?     As it turned out, I was never able to answer these questions because the spotlight (聚光灯) was waiting for me. I grasped my hands tightly together, drying off the sweat.     Slowly I walked to the mud-brown piano in the center of the room. It contained 88 demanding keys, which were waiting impatiently to be played. I swallowed the golf-ball-sized lump (隆起部分) in my throat and sat down. Slowly, I opened the music. Next, I rested my still shaking hands on the ivory (象牙色的) keys.     As my fingers played across the keys, I was becoming more unsure of my preparation for this moment. But the memory of my years of training came flooding back. I knew that I had practiced this piece so many times that I could play it backwards if requested.     Although at one point I accidentally played two keys instead of the intended one, I continued to move my fingers automatically (自动地).     My eyes burned holes into (were fixed on) the pages in front of me.     There was no way that I was going to lose my concentration. To keep this to myself, I leaned forward and focused carefully on the music.     When I came to the end of the page, a warning went off inside my head: DON’T MAKE A MISTAKE WHEN YOU TURN THE PAGE!     Needless to say, I obeyed myself with all my heart and mind. And, proud of my “page-turning” feat (技艺), I finished the rest of the piece without making a single mistake.     After the final note died away, a celebration went into action inside my head. I had finished. I had mastered the impossible. 59. The author was nervous before the performance because _______.     A. his or her mother and father weren’t present     B. the strong spotlight was shining onto the stage     C. he or she hadn’t mastered the entire piece     D. he or she had never performed in public before 60. The underlined phrase “mess up” in Paragraph 3 probably means ________. A. put into disorder       B. forget about       C. stop halfway      D. do well in 61. The author _________.     A. didn’t make any mistake in the performance     B. felt better at the beginning of the performance     C. paid all attention to nothing but his / her performance     D. lost his / her concentration sometimes during the performance 62. What did the author feel about his / her performance?     A. He / She thought it was comfortable and successful.     B. He / She thought it was very difficult but successful.     C. He / She thought he / she had never made a mistake during the performance. D. He / She thought he / she played through the piece carefully but light-heartedly.