must have been a pleasant experience— yeah, we ourselves

The doctor is now very busy, many patients are waiting _______outside his office.[ ]

xperts agree that human activities such asthe clearing of large areas of forests, and farming on a large scale _________the problem of global warming

know, the coming ofradio in this century made ocean sailing much ______.

The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?—____ my students have a try?