关于我国四大高原的叙述，正确的是(     )

一个数的 $\frac{3}{5}$ 是18，这个数是____？

苯与浓硝酸、浓硫酸制硝基苯的实验中，三种原料混合的顺序是 ____；要得到纯净的硝基苯，需经过：水洗→5% NaOH溶液洗涤→水洗→无水CaCl₂干燥→ ____（填写操作），得到纯硝基苯．

    The Readers is a popular TV show.It invites different people to read aloud on the stage.The1also tells the moving stories behind those people.They can read everything2poems，books，and letters.By reading aloud，the words on the paper come to 3.

    Many people are fans of the show.They begin to4reading aloud at home.Now，the show gives people a5place to read across China.It is a reading pavilion(朗读亭).They are in many cities，including Shanghai，Hangzhou and Xi'an.

    The pavilion is very6.Only one person can come into it each time.There is a microphone(麦可风)in it and it records people's7.Everyone can read for three minutes in the pavilion.They can read  8they like.The show will pick some of the readers and invite them to read on TV.

    People of all9read in the pavilion."Reading should be just like singing and talking，"said Dong Qing，the producer of the show."We can express our true10by reading aloud."