试题题干
WORD FORMATION
Complete the following sentence with the proper form of the word in the bracket.
(pollute) Geologists can provide the essential background information on rock and soil chemistry as well as the chemical forms of heavy metal
.
参考答案
试题解析
此处缺少名词。
of+名词/动名词（动词+ing）/ 代词……，本题不缺代词，所以应该接名词或动名词。heavy是形容词，修饰名词，所以空格处应该是名词形式。所以变pollute为名词形式pollution。
句意：地质学家可以提供岩石和土壤化学的基本背景资料以及重金属污染的化学形式。