قمائن الأسمنت النار تجربة تابع
مزايا التحديث باوستيل لوحة الثقيلة مطحنة. Down Syndrome CAGS. Down syndrome DS is the most common genetic cause of mental retardation affecting one in 700 live births The phenotype of DS is complex and variable in severity among individuals including mental retardation and cognitive deficits heart defects hypotonia motor dysfunction immune system deficiencies ...