Can you define and give an example of an observation?

Which best describes red blood cells? a. they are colorless b. they protect against disease-carrying microorganisms c. they transport oxygen throughout the body d. they aid in blood clotting

According to the big bang theory, after the "bang," the universe remained dark until about  300,000 yearsone billion yearsthree minutesthree billion years  later, when neutral atoms began to form.

Which of the following two events occur to create a sea breeze? select all that apply. warm air rises on the ocean and moves toward the land to cool warm air rises on land and moves toward the ocean to cool cool air moves from the ocean to be warmed by the land cool air moves from the land to be warmed by the ocean