_______ the teachers in their school is about 200 and one fourth of them are _______ teachers.
A：A number of; women
B： A number of; woman
C：The number of; women
D：The number of; woman
七年级学生赵佳上中学以后，父母发现他变了，不愿与父母交流，总爱和父母“顶牛”，对着干。这反映了青少年心理发展的特点是（ ）
把一张厚度为0.1mm的纸对折8次后厚度接近于（ ）.
