单项选择题
A. our brains shrink as we grow old B. the front section of the brain does not shrink C. seventy-year-olds have better brains than sixty-year-olds D. brain contraction may vary among people of the same age
A. showing their own interest in other children B. encouraging their interest in other children C. playing games with them D. buying them more toys
A. There are many forms of communication in existence today. B. Verbalization is the most common form of communication. C. The deaf and the mute use an oral form of communication D. Ideas and thoughts can be transmitted by body language.