--- Look! The plane is sending up signal “SOS”. It ________ be in danger.
---We’ll go to Beijing for vacation. ---_______.
Work hard, ______ you won't pass the exam.
I have ______ money than he, but I am ________ than he.
He helped me ______ my lost book.
---- Did he go to school when he was young? ---- No, he taught ________ at school.