Lucy has a great sense of humor and always  keeps her colleagues ___ with her stories.   [ ]

A. amused                  

B. amusing  

C. to amuse                

D. to be amused

（1）如图是氢氧化钙的溶解度曲线，从图中你能得到的信息是（写出一条即可）______．

（2）若使20℃时不饱和的澄清石灰水变成饱和溶液，可采取的措施是______、______．