2. which statement about compounds is true?
a. compounds are chemical substances
b. compounds form between two or more elements
c. both a and b
d. none of the above

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.

Been sitting here trying to take this test and don't know this answer! place the events of a feedback mechanism associated with body temperature in the correct order. ·nerve cells send message from skin to the brain ·body returned to normal temperature around 98.6 degrees f ·temperatures regulation center in the brain sends out signals ·body temperature exceeds 98.6 degrees f ·sweat glands throughout the body activate to cool off skin surface it is a 1 through 5 question in biology!

The model illustrates a process by which a substance is taken up by a cell. which statements describe the process? a. the model shows the process of endocytosis. b. the process shown in the model requires energy from the cell. c. the cell membrane in the model remains intact throughout the process. d. the model shows the process of facilitated diffusion.