I some stuff A)'ve done B)'s do C)'s doing D)'s did E) 've

A and E

Step-by-step explanation:

If the answer was A, it would translate to:

I have done some stuff.

If the answer was D, it would translate to:

I have some stuff.

Both of the sentences are grammatically correct, so A and E are the answers.

Incorrect:

B. - I's do some stuff - doesn't make sense

C. - I's doing some stuff - doesn't make sense

D. - I's did some stuff - doesn't make sense

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.

the answer is a

step-by-step explanation: