题目

Scientists often see the first ten years of a child's life as the window of opportunity,_36_And studies show that the following activities can benefit their brain greatly. _37_ Free playtime has always been an important part of being a kid,but it is also important to a child's development.Free play not only helps kids develop different skills,it also helps them develop into happy healthy adults in the future. Read with kids. Reading has long been known to improve children's intelligence._38_For parents who don't have much time, just surrounding your kids with books goes a long way too. 右图为元素周期表第三周期的局部，据此判断下列说法中正确的是：A．它们都属于金属元素B．1个铝原子的质量是26.98gC．钠元素的一个原子质子数为l1D．镁元素的相对原子质量为l2