I need help with 2,3 and 4 please!

electronic measurement tools display data on a screen after waiting for several minutes.

while some business owners prefer manual record keeping systems, most businesses use an electronic record keeping system - making it easier to capture information, generate reports and meet tax and legal reporting requirements.

explanation:

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.