Eating _______ sweet food is not good for our health (健康).
A:too many
B:too much
C:many too
D:much too
经测定,由甲醛(CH2O)、醋酸(CH3COOH)和丙酮(CH3COCH3)组成的混合物中,氢元素的质量分数为X%,则其混合物中氧元素的质量分数是()