They kept trying _________ they must have known it was hopeless.
Tom pretended________it, but in fact, he knew it very well.
The stream________during the hot summer, but it is full of water in spring.
The beggar’s suffering couldn’t arouse any ________ ,who had lost his shirts because of being addicted to gambling.
The old professor has three sons,________are doctors.
Tom ________ two of his classmates ________ invited to the party.