I wanted to buy a copy of The Youth, but there was _______ left in the bookshop._______has just bought the last one.
—He plays basketball so well! Who taught _______? —He learnt it by _______.
—_______ 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.