Answer;
-Pure chemical substance and element
Explanation;
-Pure substances are substances that are made of only one type of atom or molecule.A pure substance can be either an element or a compound, but the composition of a pure substance doesn’t vary.
-An element is a pure substance that cannot be broken down into different types of substances by chemical means. All elements are pure substances. An element is composed of a single kind of atom. An atom is the smallest particle of an element that still has all the properties of the element.
-Tungsten is an element and therefore a pure substance.
It means wolf are begining to disseaper. They are going to be extinct.
The answer is the first one because it doesn't create gases and, the third one doesn't even make any sense so its definitely not that one