Look at the pride on Tom's face. He __________ to have been praised by the manager just now.
________, I attended the meeting instead of him last week.
When you read the book, you’d better make a mark ______ you have questions.
I didn’t see your sister at the cinema. If she ______, she would have met my brother.
____ all behavior is learned behavior is a basic assumption of social scientists.
By the middle of the 21st century , the vast majority of the world’s population ________ in cities rather than in the country.