Which statement about reaction rates is true?

a. a catalyst slows down the reaction rate.
b. changing the surface area affects the reaction rate.
c. changing the amount of reactants will not change the reaction rate.
d. changing the temperature cannot speed up a reaction rate.

In all living cells dna controls cellular activities by

The climate of the continental united states is generally 1. tropical 2. temperate 3. arctic 4. highland

Miner's coal distributors does not mine coal itself, nor does it even store or handle the coal. instead, miner's solicits orders for low sulfur coal from other firms, then purchases the required amount from suppliers and directs them to ship the coal to its customers. what is miner's