1-1 Differentiate hypothesis, observation, theory, and law

1-1-1. Consider the following statements: "A drop of alcohol on a lab bench disappears after 5 minutes. The drop disappeared because molecules of alcohol moved apart and spread into the entire room." These statements, respectively, are:
A. hypothesis and theory, B. observation and hypothesis
C. observation and theory, D. law and theory

1-1-2. Consider the following statement: "Matter expands when heated." This statement is an example of :
A. a law, B. a theory, C. a hypothesis, D. an observation

1-1-3. Which of these statements is/are true?
1) It is good to do research on a problem or question before formulating a hypothesis.
2) It is not possible to prove a theory.
A. 1 only, B. 2 only, C. both, D. neither