TEAS Reading Comprehension Practice Test 3

The word “interstellar” means the space between stars.
The sentence speaks of “the scientific hypothesis that the expanses between the stars ate devoid of matter.” A hypothesis can be either confirmed of falsified by any new discovery. So, among the choices for the second missing word,“demolished” is the only word, which has one of these meanings.
The theory that the expanses between the stars are devoid of matter would certainly have been demolished, if it had been discovered that there are molecules in interstellar space. Thus, the word “molecules” is well to give a cogent meaningto the sentence. So, “molecules; demolished” is the answer.