______
A. No one knows for sure when they came into being.
B. No one knows exactly where they were first made.
C. No one knows for what purpose they were invented.
D. No one knows what they will look like in the future.
______
A. Measure the speed of wind.
B. Give warnings of danger.
C. Pass on secret me.
D. Carry ropes across rivers.
Questions 23 to 25 are based on the passage you have just heard______
A. She was a tailor.
B. She was an engineer.
C. She was an educator.
D. She was a public speaker.
Questions 20 to 22 are based on the passage you have just heard.______
A. People differ greatly in their ability to communicate.
B. There are numerous languages in existence.
C. Most public languages are inherently vague.
D. Big gaps exist between private and public languages