单项选择题
A. a secretary who does your business or social writing B. a machine that does writing for you C. a public school where writing is taught D. a person who earns a living by writing for others
A.to B.in C.for D.on
A. how people’s brains shrink B. the way of making people live longer C. the size of certain people’s brains D. why certain people aged sooner than others