You will never know the result ______ you try it by yourself.
The scientists ________ on the new medicine for two years. They will succeed in no time.
That rude man seldom uses kind words, ________?
The policeman caught the drunk driver, but he didn’t remember ________ the old lady.
After the conversation with the teacher, Jenny’s mother looked a little ________.
We just hope that Tom will bring ________ good news back home this time.