There is a lot of smoke coming out of the teaching-building there.—Really?It _________ be a fire,most probably.

In many ways China’s rapid growth has been seen as a ______ to improve thecooperation with other countries.

Mike will go abroad tomorrow. I am going to _____ at the airport.

When my sister phoned me, I could not hear clearly what she was _____

an was that the two companies should first reach an agreement on the basic principle, the details later.