The staff(员工) of the school ______to the expert’s lecture．for they feel interested in it．
| A．are listening | B．is listening | C．1istens | D．has listened |
With my hand-held Reader, I’ve read more books in the past six months than I ________ in the past six years.
| A．doing | B．did | C．have | D．do |
Since then, more than 2 billion apps have been downloaded at prices ________ free to $900.
| A．ranging between | B．ranging from | C．rang between | D．rang from |
My arrival was timed perfectly; it was the second weekend of November, when the world largest wine auction ________.
| A．held | B．was being held | C．was held | D．was to hold |
When McKie brings friends or volunteers to the area where she works, most of ________ spend the first day sobbing.
| A．them | B．whom | C．that | D．which |
_______ in the 1800s and first mass-produced in Germany, the harmonica(口琴) was designed to play simple folk tunes.
| A．Being invented | B．Inventing | C．Invented | D．Having invented |