Vitamin D helps our bodies make a special chemical,and this special chemical, ____ , affects our brains,making us feel happy.
---He is fifteen years younger than you. ---?
Although his experiments were designed to support the ideasthe influence of environment upon plants, Mendel found that many characteristics were passed on from one generation to the next.
They are experienced porter(搬运工)who know how tothe weight of the rocks they carry.
So fastat the lecture that I missed much of it.
Nothing he did was helpful to solve this problem,?