[单项选择]For light to travel across the solar system, it will take ______.
A. a year
B. nearly a day
C. two months
D. thirty minutes

[单项选择]For light to travel across the solar system, it will take ______.
A. a year
B. nearly a day
C. two months
D. thirty minutes

[单项选择]The solar system in astronomy consists of the sun and its planets. EXCEPT （）, all the planets got their names from Greco-Roman mythology.
A. Mars
B. Earth
C. Venus
D. Jupiter

[单项选择]All the planets in the Solar system except Mercury and Venus have natural satellites, — objects that revolve around the planets.
A. ( which
B. ( which are
C. ( of which
D. ( and which

[单项选择]There may be, somewhere outside the solar system, intelligent life ______ messages to us.
A. sends
B. sent
C. sending
D. has sent

[单项选择]So far, the solar system most like ours that have been discovered is ______.
A. in the group of stars known as Great Bear
B. 2.5 times as big as Jupiter
C. smaller that our system
D. impossible for us to reach at present time

[单项选择]Of all the planets in this solar system, Mercury is {{U}}nearest{{/U}} the Sun.
A. most like
B. closest to
C. hotter than
D. heavier than

[单项选择]All the planets in solar system EXCEPT ______ got their names from Greeo-Roman mythology. ( )
A. Earth
B. Mars
C. Jupiter
D. Pluto

[单项选择]Solar energy causes
A. less pollution than oil
B. the same pollution as oil
C. more pollution than oil
D. financial problem

[单项选择]Communication satellites generally use solar cells as their source of electric power, although some {{U}}test{{/U}} satellites have used thermoelectric generators.
A. superior
B. authorized
C. former
D. experimental

[单项选择]下列哪种组织成分或器官在T₁WI及T₂WI上均为高信号
A. 空气
B. 肝
C. 脂肪
D. 水
E. 钙化

[单项选择]Wi-Fi联盟制定的安全认证方案WPA（Wi-Fi Protected Access）是（）标准的子集。
A. IEEE 802.11
B. IEEE 802.11a
C. IEEE 802.11b
D. IEEE 802.11i

[单项选择]Wi-Fi联盟制定的安全认证方案WPA(Wi-Fi Protected Access)是______标准的子集。
A. IEEE 802.11
B. IEEE 802.11a
C. IEEE 802.11b
D. IEEE 802.11i

[单项选择]Charity officials are concerned that volunteers will not be able to distribute ______ water to the victims of the earthquake.
A. overall
B. enough
C. all
D. full

[单项选择]

The new global satellite communications systems will offer three kinds of service, which may overlap in many different kinds of receivers.
VOICE. Satellite telephones will be able to make calls from anywhere on the earth to anywhere else. That could make them especially useful to remote, third world villages (some of which already use stationary satellite telephones), explorers and disaster-relief teams. Today’s mobile telephones depend on earth-bound transmitters, whose technical standards vary from country to country. So business travelers cannot use their mobile phones on international trips Satellite telephones would make that possible.
MESSAGING. Satellite massagers have the same global coverage as satellite telephones, but carry text alone, which could be useful for those with laptop computers. Equipped with a small screen like today’s papers, satellite messages will also receive short messages.
TRACKING. Voice and messaging systems will
A. business travelers use mobile phones on international trips
B. possible calls from anywhere on earth to anywhere else
C. explorers happy
D. all above