---Look! It must be Jack on the playground.---It _____ be him. Because I saw him enter the school library just now.
—_______ can I keep the books? —Two weeks.
My mother often tells me _______ my classmates when they need.
Do you prefer _______?
You should _______ the doctor’s advice and _______ the medicine on time.
Sally sings pretty _______ and she is also _______ at dancing.