Food safety is important. Rules____ to stop people from food pollution.
Which “ai” in the following word has a different pronunciation from the others?
Hangzhou is ______ most beautiful tourist city and I believe I’ll come here for _____ second Time.
He finds hard to finish the work in two days.
—Is Tom at home? —No, he ____ to town.
Our school is different _______ theirs. Ours has many after-school clubs.