单选题
Directions: In this part you will read a selection of texts, such as magazine and newspaper articles, letters, and advertisements. Each text is followed by several questions. Select the best answer for each question and mark the letter (A), (B), (C), or (D) on your answer sheet.
Questions 153-155 refer to the following chart.
CROWDING THE PLANET

This chart shows how much the world's population grew between 1900 and 2000, and how much experts believe it will grow by 2025. The numbers are in billions.
单选题 What was the world population in 1950?
【正确答案】 C
【答案解析】The world population in 1950 was 2.5 billion. Choice (A) confuses half a billion and 2.5 billion. Choice (B) was the population in 1925. Choice (D) confuses 5 billion and 2.5 billion.
单选题 In what year did the population reach 4 billion?
【正确答案】 D
【答案解析】In 1975 the population reached 4 billion. Choice (A) is when the population reached I billion. Choice (B) is when the population reached 2 billion. Choice (C) is when the population reached 2.5 billion.
单选题 When was the population under 2 billion?
【正确答案】 A
【答案解析】In 1900 the population was 1 billion, half of 2 billion. Choices (B), (C), and (D) have populations of 2 billion and over.