-Excuse me.How long can I keep the book?-You can return it by the end of this month.
_______ of the materials I listened to at the beginning of the exam _______ easy.
_______, Coca-Cola began to enter China’s market.
______black—headed gulls(红嘴鸥) come to Kunming to spend their winter every year.
Helen is my friend. She is in ______ at Beijing No.11Middle School.
---Look at that tall building! ---It is _______tallest building in the city.