As they _____ in the snowstorm in the deep mountains, they had great _____ in getting in touch with the outside world.
-- I have got a headache. -- No wonder. You_________ on the math exercises too long.
Attention, please. All of you students _______ remain in their seats until all the papers have been collected.
____ it rain tomorrow, we would have to put off the visit to the Yangpu Bridge.
Whoever is never ______ with the progress he has made will be a success.
Canada is a country ________ many different nationalities as well as one with foreign immigrants __________ the majority of its population.