The police can’t decide whether the suspect is guilty because he could prove he was________at the time of the crime.
Mr. Wu___this math problem____him many times, but he still doesn’t understand it.
Bob doesn’t know ________ to write about.
--How many students have passed the examination? -- _______.
_________ creates the feeling of harmony and also represents sadness.
My grandma _________ Chinese food ________ Western food.