看图读一读填空，把句子代码填在正确的横线上。
A. There's a blackboard in it. There are eighteen desks and eighteen chairs in it.
B. There are three books in it. C. There's a ruler. D. There's a big library.
____ ____ the workers are working!
用微粒的观点解释下列事实．
（1）碘固体（I2）和碘蒸气都能使淀粉变蓝．
（2）等质量的碘固体和碘蒸气比较，碘蒸气的体积远大于碘固体．
