A-G pls help me i got scammed for 70 points no lies

Which prevent errors in dna replication? a. helicase enzyme checks the dna for errors. b. each base can attach to only one other type of base. c. ribosome enzymes prevent errors from happening. d. dna contains no complementary base pairs.

Me the formula cacl2 represents the compound

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