You have failed two tests. You’d better start working harder, ____ you won’t pass the course.

live in the country or have ever visited there, ______ are that you have heard birds singing to welcome the new day.

Nancy, which dress do you like better, the yellow one____ the blue one–The blue one.

(2014·宝鸡三检)By the time the girl comes back to life，scientists probably________a cure for this incurable disease

Each person has his / her uniquecharacter which ____ him / her from others