It ________ be the vocabulary that caused you the problem in the exercise because you know a lot of words.
Jack almost fell off the cliff, but managed to _____ until help came.
It isn't so much whether he works hard; the question is whether he works _____.
Alice was very sorry to hear that her grandmother had _____ two days before.
People cannot but feel _____, for they simply cannot understand how he could have made such a stupid mistake.
The chances of discovering life on Neptune are about a million _____.