______ label to each of the trees, with detailed introduction of their features, and visitors will know more about them and how to protect them.
“Did Jim come?” “I don’t know. He _______ while I was out.”
“Look at these tracks. It _______ be a wolf.” “Don’t be so sure. I think it _______ be a fox.”
“Show me your permit, please.” “Oh, it’s not in my pocket. It ______.”
“Is there a flight to London this evening?” “There _______ be. I’ll phone the airport and find it out.”
Why did you just sit and watch? You _______ me.