妈妈买了12本连环画。妹妹看了7本，还有多少本没看？'O,W1E'd,I)},y0Y'T
算式：提示)o,F0w:\/})l3C)p'O,W1E'd,I)},y0Y'T
答：还有,t+c.t:p,t1n*@)n3Z/d:[本没看。'O,W1E'd,I)},y0Y'T