Be ___________ ---you can’t expect me to finish all this work in so little time.

This is a______ but extremely difficult technology in the future.

The second half of his voyage was __________ dangerous part, during which he sailed round the Cape Horn.

—He thinks that girls are smarter than boys when it comes to learning English．—But two years ago he thought____．

Interest is as ________ to learning as the ability to understand, even more so.