[简答题]什么时“编组列车”？

American Indians played a central role in the war known as the American Revolution. To them, however, the dispute between the colonists and England was peripheral. For American Indians the conflict was a war for American Indian independence, and whichever side they chose, they lost it. Mary Brant was a powerful influence among the Iroquois. She was a Mohawk, the leader of the society of all Iroquois matrons, and the widow of Sir William Johnson, Superintendent of Indian Affairs. Her brother, Joseph Brant, is the best-known American Indian warrior of the Revolution, yet she may have exerted even more influence in the confederacy than he did. She used her influence to keep the western tribes of Iroquois loyal to the English king, George 111. When the colonists won the war, she and her tribe had to abandon their lands and retreat to Canada. On the other side, Nancy Ward held positions of authority in the Cherokee nation. She had fought as a warrior in the war against the Creeks and
A. Mohawk.
B. Roquois.
C. Cherokee.
D. Creek.

In China phone talk is expensive. If you want to make it cheaper, make phone calls using the Internet, which can cost as little as 30% or even 5% of a traditional call.
But changing your DDD (domestic direct dial) and your IDD (international direct dial) calls for the net version, called voice over the internet protocol (互联网协议) or VoIP, requires you to choose between different types of technology, with different advantages.
If a telephone connection was a road, a regular phone call allows you and the person you are calling to share the road without anyone else. On this empty road, the connection is fast, efficient, and uninterrupted. But with VoIP technology, your voice is broken into millions of separated packets of information that share the road with all the billions of other bits of information on the Internet. When the packets reach the person you are calling, they are gathered to resemble your voice. Depending on which type of VoIP you are using, the
A. to introduce a new technology called VoIP
B. to inform that IP phone calls are sometimes quite awful
C. to tell us that IP calls are dependent on personal computers
D. to compare the IP calls with the traditional phone calls