13. The students must have obeyed their teachers.

a)Their teachers might have obeyed by
the students.
O
2)Their teachers might have been
obeyed by the students.
O
3)Their teachers must have been obeyed
by the students.
O
4)Their teachers must have obeyed by
the students.​

The answer is 3

Explanation:

A is automatically out ruled because "might" contradicts the "must" in the sentence above.

2 Also contradicts the "must" in the sentence above.

3 Does not contradict the "must" and makes grammatical sense. Therefore, 3 is the answer

4 Doesn't contradict the *must" but does not make grammatical sense.

some attention getter quotes to support your thesis regarding brain work could be the following: :

a. storage capacity of your brain is virtually unlimited.

b. your brain produces sufficient electricity to light-up a small bulb.

c. different brain circuits are involved with reading aloud or silently.

d. your brain by itself does not feel pain.

e. reading allows your brain to download info directly.

f. brains of two musicians performing together can synchronize.