The boy is very clever.He can work out difficult problems.(合并为一句)
It is very clever the boy work out difficult problems.
The letter "x" often represents a(n) (known) number in some Math exercises.
Can you tell me the (pronounce) of the word "agriculture"?
Sorry, I don't know, either.
Who gets up the (early) in your family?
My mum. She cooks breakfast for Dad and me.
You always look unhappy !What (worry) you?
I really can't balance my study and hobbies.
The librarian was at me and seemed friendly. (smile)