— I hear Prof.Huang will give us a talk ______ the History of Diaoyu Islands this weekend.— That’s great!A. on B. to C. at
The light bulb ______ by Edison in the middle of the 1780s.
The old scientist has made a great contribution the moon.
—What is the table made _______? —Wood.
Many countries have a lot of rockets into space.
—How can I learn English well? —You will learn it well ________ you practice speaking it often.