-Why is you rprofessor so happy recently?-Because the throry she insisted on__________correct.A is proved B proving C was proved D has proved
_________a reply, he decided to write a sixth letter.
The secretary worked late into the night, ______a long speech for the president.
To master a foreign language,______.
They have had a long and bitter struggle _____their living conditions.
Tom kept quiet about the accident _______lose his job.