Before starting a lab you should select all that apply. tie loose hair back clean work table with 10% bleach solution wear loose clothing know the location of all exits

Option A and D

Explanation:

Before starting any lab activity it is essential to take all safety measures. Therefore a person who is working in a lab irrespective of gender must do the following

a) Wear the laboratory coat and shoes

b) Must tie up all loose hairs

c) Wear gloves and hair mask

d) Must know all the routes of escape in case of emergency

e) Should not wear loose clothing that could become a start point of accident

Hence, option A and D are correct

the answer is b.) hydrogen bonds between bases.