I ___________ frustrated when I wasn’t sure of thecorrect answer.

People along the river didn’t allow them to ______ a factory so as not to pollute the water.

.Would it be ________ for you to pick me upat four o’clock and take me to the airport

______ I admit that there are quite a few problems, I don’t agree that they cannot be solved

lculation of the result of the exam_______ to the fact, but he failed again．