Mark all those of the following that are appropriate uses of glassware in the laboratory:

a. to accurately measure 20.00 +/- 0.02 ml, use a 10.00 ml pipet making two deliveries.
b. to accurately measure 20.00 +/- 0.02 ml, use a 150 ml beaker with marked graduations.
c. to quickly approximate 20 ml, use a 10.00 ml pipet making two deliveries.
d. to quickly approximate 20 ml, use a 150 ml beaker with marked graduations.