[单项选择]The average (arithmetic mean) number of trees per acre in a 40-acre plot is 140. If a 10-acre section of the plot contains 90 trees per acre, how many trees are there in the remaining 30 acres
A. 5,700
B. 4,700
C. 4,200
D. 3,600
E. 2,700

[单项选择]The average (arithmetic mean) of five number is 26. After one of the numbers is removed, the average (arithmetic mean) of the remaining numbers is 25. What number has been removed ？（）
A. 20
B. 25
C. 26
D. 30
E. 32

[单项选择]

The average (arithmetic mean) of 3 different positive integers is 100 and the largest of these 3 integers is 120, what is the least possible value of the smallest of these 3 integers ？（）

A. 1
B. 10
C. 61
D. 71
E. 80

[单项选择]In a retail store, the average (arithmetic mean) sale for month M was d dollars. Was the average (arithmetic mean) sale for month J at least 20 percent higher than that for month M ？（）
(1)For month M, total revenue from sales was $3,500.
(2)For month J, total revenue from sales was $6, 000.

A. 条件（1）充分，但条件（2）不充分.
B. 条件（2）充分，但条件（1）不充分.
C. 条件（1）和（2）单独都不充分，但条件（1）和条件（2）联合起来充分.
D. 条件（1）充分，条件（2）也充分.
E. 条件（1）和条件（2）单独都不充分，条件（1）和条件（2）联合起来也不充分.

[单项选择]What is the average (arithmetic mean) of 3³⁰, 3⁶⁰, and 3⁹⁰
A. 3⁶⁰ B. 3¹⁷⁷ C. 3¹⁰ + 3²⁰ + 3³⁰
B. 3²⁷ + 3⁵⁷ + 3⁸⁷ E. 3²⁹ + 3⁵⁹ + 3⁸⁹

[单项选择]If the average (arithmetic mean) of 10, 20, 30, 40, and x is 60, what is the value of x
A. 50
B. 60
C. 100
D. 150
E. 200

[填空题]Men have cut down a large number of trees, ____________(结果却发现他们失去了最好的朋友).

[单项选择]A. The lifecycle of trees.
B. The number of trees.
C. The intensity of solar burning.
D. The quality of air.

[单项选择]

Healthy trees are important to us all. Trees provide shade, beauty, and homes for wildlife. Trees give us products like paper and wood. Trees can give us all these only if they are healthy. They must be well cared for to remain healthy.
Your trees’ trouble may be you yourself. People spend much time and money to plant and maintain trees. Trees improve the looks of homes, parks, business, and public buildings. Yet, people who love trees the most may be the ones who cause them injury. Of course, they do not do this on purpose. They are most likely not aware of the kinds of things that injure trees. There are many people-caused tree injuries. You should become aware of them and avoid them. Learn the things that can help to keep your trees healthy.
Healthy trees are beautiful. They make our world a pleasant place to live ill. Unhealthy trees are not as beautiful. They make our world less pleasant. Healthy trees help to cool and clean the air. They can even deade
A. beautiful
B. old
C. healthy
D. young

[简答题]mean temperature

[单项选择]What does the woman mean

What does the woman mean
A．She will show him the way.
B．She doesn’t catch his meaning.
C．She doesn’t understand English.
A. She will show him the way.
B. She doesn’t catch his meaning.
C. She doesn’t understand English.

[填空题]What does "In Touch With Us Tomorrow "mean
It means（）and have contact with us.

[单项选择]What happens to trees each year
A. Their tings get thinner and thinner.
B. They add a ring of wood.
C. Their rings get darker in color.
D. They become more valuable.

[单项选择]What does Mike mean
A. He likes both Beijing and New York.
B. He likes neither Beijing nor New York.
C. He likes Beijing, but he doesn"t like New York.