Studies show that Americans chat on their phones for more than five hours a month, _____ Europeans.
So suddenly ________that the animals in the zoo looked very frightened during the total solar eclipse (日全食).
—Have you finished your book report? —Not yet. I couldn't________on it with so loud music next door last night.
Once we have________some knowledge, things do not become more difficult, but comprehensible.
The chief editor demanded that the article ________immediately.
Tom is a promising student. I am sure that with his________effort, he will make a very successful scientist.