The signal words for beginning events include ().
A、words to be most important
B、signal words
C、words after verbs
D、verb phrases
A.prepositional words
B.plural words
C.metapherical words
D.transitonal words
In Africa, people learned to send messages by beating on a series of large drums (鼓). Each drum was kept within hearing distance of the next one. The drum beats were sent out in a special way that all the drummers understood. Though the messages were simple, they could be sent at great speed for hundreds of miles.
In the eighteenth century, a French engineer found a new way to send short messages. In this way, a person held a flag in each hand and the arms were moved to various positions representing different letters of the alphabet (字母表). It was like spelling out words with flags and arms.
Over a long period of time, people sent messages by all these different ways. However, not until the telephone was invented in America in the nineteenth century could people send speech sounds over a great distance in just a few seconds.
According to this passage, the Roman way of communication depended very much on______.
A.fine weather
B.high tower
C.the spelling system
D.arm movements
It can be inferred from the first paragraph that__________ .
A.every glance has its significance
B.staring at a person is an expression of interest
C.a gaze longer than three seconds is unacceptable
D.a glance conveys more meaning than words
If you hold eye contact for more than three seconds, what are you telling another person? Much depends on the person and the situation. For instance, a man and a woman communicate interest in this manner. They typically gaze at each other for about three seconds at a time, and then drop their eyes down for three seconds, before letting their eyes meet again. But if one man gives another man a three-second-plus stare, he signals— "I know you. " "I am interested in you. " or "You look peculiar and I am curious about you. " This type of stare often produces hostile feelings.
It can be inferred from the first paragraph that______.
A.every glance has its significance
B.staring at a person is an expression of interest
C.a gaze longer than three seconds is unacceptable
D.a glance conveys more meaning than words
A.Demodulation reference signal for PUSCH
B.Phase-tracking reference signals for PUSCH
C.Demodulation reference signal for PUCCH
D.Sounding reference signal