更多"At one time, scientists thought the"的相关试题:
[填空题]At one time, scientists thought the space between Earth and Sun was a vacuum. But we now know that the sun fills it with gusts of hot, electrically charged atomic (36) called the solar wind. Sometimes this wind blows hard. When the Sun’s outer layer is very active, it (37) nearly one-third of its gaseous matter outward at supersonic speeds.
The U.S. government’s oceans and atmosphere agency NOAA, has a Space Environment Center to monitor these (38) . The center’s director, Ernest Hildner, says (39) solar emissions are not dangerous to people on the ground, but can be a (40) to airplane occupants and astronauts. They can also shut down satellites, power networks, communications, and other technical systems.
Scientists have long known that solar storms are generated internally by the sudden (41) of magnetic energy rising to the surface. Like a tightly (42) rubber band, the Sun’s magnetic fields can
[单项选择]There’s no comparison between them, one （） clearly much better than the other.
A. being
B. was
C. be
D. having been
[单项选择]Ability to Rollover Unused Vacation Time
One of the benefits employees really want is the ability to rollover their unused vacation time． (29) you may indeed have some (30) mem-bers who abuse this benefit，the vast majority (31) use their vacation time wisely． (32) likely is it that anyone is going to save up months (33) vacation time and then use it all at once
The reality is that your employees have earned those days，and they would like to feel assured that they have (34) in case of an emergency．A short memo (35) them of the importance of using their vacation time wisely should be a sufficient safeguard (36) vacation-time abuse．
The bottom line for all employers (37) 。that you should be constantly looking for ways to attract and retain quality staff． (38) ．that means a bit of strain (39) ．your bottom line in the short (40) ，the return on your in
A. during
B. of
C. among
