题目

The United Nations Environment Program is calling for urgent action to reduce growing risks from chemicals. Better management of chemicals could save millions of lives and billions of dollars. An estimated one hundred forty-three thousand chemicals are now produced. Yet only the report says only a small number of these chemicals have been studied for their effects on human health and the environment. It says death and disability rates are high from the unsafe use of chemical products. Sylvie Lemmet, director of the U.N. Environment Program, says poor management of chemicals has a high e下列表达方式或说法错误的是A．氯化氢分子的电子式：B．3 2He和4 2He是两种不同的核素C．S2-的结构示意图D．ⅦA族元素其简单阴离子的核外电子层数等于该元素所在的周期数