单项选择题
A．The two sides of their brain develop simultaneously. B．They are better able to adapt to the surroundings. C．Their bones mature earlier. D．They talk at an earlier age.
A．Submit no more than three letters. B．Present a new letter of reference. C．Apply to three graduate schools. D．Send Professor Smith a letter.
A．It is a breakthrough in the study of the nerve system. B．It may stimulate scientists to make further studies. C．Its result helps understand babies’ language ability. D．Its findings are quite contrary to previous research.