According to the passage, what does the word "which" in line 5 refer to?

Read the passage and choose the correct answer for each question

The Stone Age was a period of history which began in approximately two million B.C and lasted until 3,000 B.C. Its named was derived from the stone tools and weapons that modern scientists found. This period was divided into the Paleolithic, Mesolithic and Neolithic Ages. During first period (2,000,000 to 8,000 B.C), the first hatchet and use of fire for heating and cooking were developed. As a result of the Ice Age, which evolved about one million years into the Paleolithic Age, people were forced to seek shelter in caves, wear clothing and developed new tools.

During the Mesolithic Age (8,000 to 6,000 B.C), people made crude pottery and the first fish hooks, took dogs hunting, and developed the bow and arrow, which were used until the fourteenth century A.D.

The Neolithic Age (6,000 to 3,000 B.C) saw humankind domesticating sheep, goats, pigs and cattle, being less nomadic than in previous eras, establishing permanent settlements and creating governments.

With what subject is the passage mainly concerned?

Into how many periods was the Stone Age divided?

Read the passage below and choose one correct answer for each question.

A UFO (Unidentified Flying Object) is any object flying in the sky which cannot be identified by the person who sees it. Sometimes the object is investigated. If people can still not figure out what the object is after an investigation, it is called a UFO. If they figure out what the object is, it can no longer be called a UFO because it has been identified.

Even though UFOs can be anything, people often use the word UFO when they are talking about alien spacecraft. Flying saucer is another word that is often used to describe an unidentified flying object.

Studies estimate that 50%-90% of all reported UFO sightings are identified later. Usually 10%-20% are never identified. Studies also show that very few UFO sightings are hoaxes (people trying to trick other people). Most UFOs are actually natural or man-made objects that looked strange. 80%-90% UFOs are identified as one of three different things: astronomical causes (for example: planets, stars, or meteors); aircraft; balloons. 10%-20% of UFOs are other causes (such as birds, clouds, mirages, searchlights, etc.)

What does the word “figure out” in paragraph 1 mean?

Another word used to describe a UFO is _________.

Which of the following developments is NOT related to the conditions of the Stone Age?

Where in the passage does the author mention the stone tools and weapons?

Choose the correct word to complete the passage

I began my teaching career nearly ten years old. I spent six years teaching in a remote village (1) ______the villagers were very poor and the living standard was low. Sometimes, I was very disappointed (2) ______bad living condition and low pay. I am really homesick. However, at that time, with my youth enthusiasm, I tried my best to devote myself to the noblest career, that (3) ______ “teaching”. I love my poor little students. They were living in poverty but they could not (4) ______from empty mind.

Read the following passage and mark the letter A, B, C,or D on your answer sheet to indicate the correct answer to each of the questions.

Television and Kids

Television is very popular and even has some benefits for kids. It helps very young children learn the letters of the alphabet, and helps other kids learn about science, cultures, and world events.

However, researchers show that too much TV is bad for children. For one thing, there is a link between watching more than four hours of TV a day and being overweight. For another thing, many TV shows are violent and upsetting. Watching these shows may cause kids to be more fearful. And of course, more time in front of the TV means less time to study. Too much TV may also be the cause of lower grades.

Experts do not agree on the solution to these problems. Some say that kids should watch only educational programs; others say kids should watch no TV at all. And others suggest teaching them to watch TV as occasional entertainment, not as an everyday hobby.

What is the passage mainly about?

Sometimes, I was very disappointed (2) ______bad living condition and low pay.

They were living in poverty but they could not (4) ______from empty mind.

The word "them" in paragraph 3 refers to ______.

However, at that time, with my youth enthusiasm, I tried my best to devote myself to the noblest career, that (3) ______ “teaching”.

According to the passage,watching a lot of TV may ______

How many percents of all reported UFO sightings are not identified?

Most of UFOs are identified as one of the following things except _________.