This is my school. There are many trees and flowers in it. It's very beautiful. The teaching building is big and tall. There is a big playground in our school. After 4:30 in the afternoon, many students come to the playground to play football and some students play table tennis in the table tennis room. There are 1,200 students and 25 classes in our school. The students all like to study. The teachers in our school are very good. They help the students to study and the students like them, too

（1）氯化铁溶液与氢氧化铁胶体具有的共同性质是　 ____　  （填正确字母序号）

A．分散质颗粒直径都在l～100nm之间          B．能透过半透膜

C．加入浓氢氧化钠溶液都产生红褐色沉淀       D．颜色都呈红褐色

（2）举出胶体化学知识在人类生活中的一个应用 ____

下列估测合理的是（　　）

下列词语中没有错别字的一项是  (       ）