Check all that apply.
hypotheses are based on observations.
hypotheses are written when experiments are complete.
hypotheses are formed from testable questions.
hypotheses are tested with controlled experiments.

An example of internal feedback working to maintain homeostasis is your a. decreased respiration rate when you are studying b. decreased heart rate when you are sad c. increased respiration rate when your muscles need more oxygen d. increased heart rate when your lungs need more oxygen

The pronunciation aid that determines the stress placed upon a syllable is the

Why are current extinctions of concern to enviromentalists?