题干

请根据“绿叶在光下制造有机物”的①﹣⑥实验步骤示意图,回答下列问题

①把盆栽的天竺葵放在黑暗处一昼夜;

②用黑纸把一片叶的部分从正面和背面遮住,然后移到阳光下照射3至4小时;

③剪下遮光的叶片,去掉黑纸

④将叶片放在盛有酒精的小烧杯中,再放入大烧杯内隔水加热一段时间

⑤取出叶片,用清水漂洗干净,然后放在培养皿里,向叶片滴加碘液;

⑥稍停片刻,用清水冲洗掉碘液.实验结果与分析:

上一题 下一题 0.0难度 选择题 更新时间:2017-12-25 01:01:49

答案(点此获取答案解析)

同类题1

任务型阅读

    Why doesn't the conductor face the audience?____As the only person with his back to the audience, the conductor is a figure who is bathed in the spotlight, but his complex work requires a high degree of musical skill, as well as an ability to extract what he desires out of the group of artists he leads--his orchestra.

    ____A person may become a conductor without graduating from the conducting department of a music school or studying in any kind of conductor's training program. However, becoming the conductor of a famous orchestra requires a great deal more than what is needed merely to join an orchestra.

    ____These naturally examine a conductor's technique and musical interpretation while he conducts an orchestra through a prepared piece of music, but they also involve a sight-reading element____The conductor then has to sit in a room and memorize the piece before coming out and leading the orchestra through the piece by memory. Not only does the conductor have to make his arm and hand motion properly, and signal all the entrances of each instrument, he has to point out intentional mistakes made by the orchestra members on the spot.

    The least capabilities a conductor must have are: The ability to memorize an entire score. A good ear for distinguishing correct notes among the music of the entire orchestra.____

    Of the conductors that meet these requirements, those with better musical insight and a higher level of charisma(魅力) will succeed.

A. The need for a common musical standard becomes necessary

B. The ability to lead a group of professional musicians

C. There are many conducting competitions

D. For this, the score of music is given to the conductor on site

E. This is how the role of the conductor came to be established

F. The role of the conductor is in fact not well understood

G. There are no examinations for becoming a conductor