_______ in the 1800s and first mass-produced in Germany, the harmonica(口琴) was designed to play simple folk tunes.
—How are you getting on with your business?—I’m glad to say it is _____.
—_____of Hangzhou has your brother covered since he came here?—About half of it, I guess
When we worked in the same office, we _____ often have coffee together.
—Where do Dr. Kleitman and his assistant come from?—I’m not sure, but their English _____Australia.
The novels written by the author sell best, but five years ago no one could have imagined how great a role he _____in the literary world.