What are the measures to prevent from sexually transmitted diseases?

answer; //the above statement is (false);

the real answer is b. scintillation counter

i believe the answer would be b. hope it : )

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.