I don’t know why UFOs are never sighted over large cities by hordes of people. But it is consistent with the idea that there are no space vehicles from elsewhere in our skies. I suppose it is also consistent with the ideas that space vehicles from elsewhere avoid large cities. However, the primary argument against recent extraterrestrial visitation is the absence of evidence.
Take leprechauns. Suppose there are frequent reports of leprechauns. Because I myself am emotionally predisposed in favor of leprechauns, I would want to check the evidence especially carefully. Suppose I find that 500 picnickers independently saw a green blur in the forest. Terrific. But so what This is evidence only for a green blur. Maybe it was a fast hummingbird. Such cases are reliable but not particularly interesting.
Now suppose that someone reports: "I was walking through the forest and came upon a convention of 7000 leprechauns. We talked for a while and I was taken down into their hole in the ground and shown pots of gold and feathered green hats. "I will reply: "Fabulous! Who else went along" And he will say, "Nobody," or "My fishing partner. "This is a case that is interesting but unreliable. In a case of such importance, the uncorroborated testimony of one or two people is almost worthless. What I want is for the 500 picnickers to come upon the 7000 leprechauns.., or vice versa.
The situation is the same with UFOs. The reliable cases are uninteresting and the interesting cases are unreliable. Unfortunately, there are no cases that are both reliable and interesting.
It is concluded from the passage that the testimony given by one or two persons is ______.

A:always worthless B:often reliable C:interesting but not reliable D:nearly worthless if it is concerned with matters of great importance

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A:always worthless B:often reliable C:interesting but not reliable D:nearly worthless if it is concerned with matters of great importance

TCP (Transmission Control Protocol) was specifically designed to provide a reliable end-to-end byte stream over a(n)______.

A:IP address B:reliable network C:socket D:unreliable internet work

TCP (Transmission Control Protocol) was specifically designed to provide a reliable end-to-end byte stream over a(n) （）.

A:

IP address B:reliable network C:socket D:unreliable internetwork

One of the main responsibilities of ICMP is to report （1）. Although technology has produced increasingly reliable transmission media, errors still exist and must be handled. IP is an （2）protocol. This means that error checking and error control are not a concem ofIP JCMP wasdesigned, in part, to compensate for this shortcoming. Howerver, ICMP does not （3）errors, itsimply reports them. Error correction is left to the higher-level protocols. Error messages arealways sent to the original（4） because the only information available in the datagram aboutthe route is the source and destination 1P addresses. ICMP uses the source IP address to send theerror massage to the source of the （5）

A:reliable B:unreliable C:available D:Unavailable

●One of the main resposibilities of ICMP is to report（）.Although technology has produced increasingly reliable transmission media, errors still exist and must be handled．IP is an （） protocol．This means that error checking and error control are not a concern of IP．ICMP was designed，in part，to compensate for this shortcoming．Howerver, ICMP does not（） errors，it simply reports them．Error correction is left to the higher-level potocols．Error messages are always sent to the original （） because the only information available in the datagram about the route is the source and destination IP addresses．ICMP uses the source IP address to send the error massage to the source of the （） .

A:reliable B:unreliable C:available D:unavailable

TCP(Transmission Control Protocol) was specifically designed to provide a reliable end-to-end byte stream over a(n) （）.

A:IP address B:reliable network C:socket D:unreliable internetwork