A landing on Mars is within the _____ of current physical theory.
There’s a feeling in me ____we’ll never know what a UFO is - not ever. (
The children were catching butterflies in the garden. Some caught a lot, and others caught ____at all.
Equipped with modern facilities, today’s libraries differ greatly from ___.
It was because of bad weather____ the football match had to be put off. (
34、If this dictionary is not yours, ____can it be?