TASK DEFINITION: In this task, you are given a sentence and a question, you would be asked to create the answer which is contained in the sentence provided.
PROBLEM: Sentence: Sliding friction is friction that acts on objects when they are sliding over a surface. Question: What type of friction is friction that acts on objects when they are sliding over a surface?

SOLUTION: sliding friction

PROBLEM: Sentence: Metallic bonds hold together positive metal ions and their valence electrons. Question: What types of bonds hold together positive metal ions and their valence electrons?

SOLUTION: metallic bonds

PROBLEM: Sentence: Population is an important level of organization in ecology and the unit of microevolution. Question: What is an important level of organization in ecology and the unit of microevolution?

SOLUTION:
population