Which of the following elements is/are represented in the spectrum below? A. Hydrogen only
B. Helium only
C. Hydrogen and helium
D. Calcium only

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

What happens when water’s salinity increases? mass decreases. freezing point decreases. buoyancy of objects decreases. the amount of dissolved minerals decreases.

Group control group #1 experimental group yes yes yes control group #2 no new drug orange juice bed rest no yes no yes ves which of the following is the best explanation of why a second control group was included in this experiment? o a. to provide the volunteers in the study with something to drink o b. to prove that the common cold cannot be cured c. to confuse anyone who is trying to steal their new drug and sell it as their own invention o d. to researchers conclude that results are related to the new drug and not to the orange juice submit e previous