The ground isn’t wet. It ________ have rained last night.

pe to take the computer course.— Good idea. ____ more about it, visit this website.

There is no experience you canhave ______ is more exciting than skating on real ice.

Not until Betty got to the airport _____ she had lost her tickets.

Martin Luther King Jr．was _____ the Noble Peace Prize of 1964 for advocating nonviolence policy in the movement for civil rights．