The basic principle utilised in LBM is that under proper conditions light energy of a

Parents speak loud in teacher selection in their child's early learning because______.

A．it is torturing to wait for news of classroom assignments

B．they consider it great to be a teacher in basic education

C．they are used to directing nearly all aspects of their child

D．it is custom to meet and argue with the school principle

echo of the shouting (11)______ the walls helps a person determine the size of the cave. With radar，however，the waves are radio waves instead of (12)______ waves. Radio waves travel (13)______ the speed of light，about300,000 kilometers in a second. A radar set (14)______ a short burst of radio waves. Then it receives the echoes (15)______ when the waves bounce(反射) off objects. By determining the time it (16)______ for the echoes to return to the radar set，a trained technician (17)______ determine the distance between the radar set and other objects. The word“radar”， (18)______ ，gets its name from the term“radio detection and ranging. ”“Ranging”is the term for detection of the (19)______ between an object and the radar set.

Besides being of critical importance to pilot，radar is (20)______ for air traffic control，for tracking ships at sea，and for tracking weather systems and storms.

(11)

A．through

B．for

C．on

D．against.

This independent organization devoted to the welfare of needy children throughout the world is seventy years old. Many children suffered hunger and homelessness at the end of the First World War. Concerned about the plight(困境) of these children, a group of British volunteers founded a new organization in 1919 to publicize the problems and help improve conditions. A founder member, Eglantyne Jebb, drew up the declaration of the "rights of the child", which was adopted by the League of Nations(later the United Nations). This charter(宪章) sums up the philosophy of Save the Children Fund's work. The basic principle is that dignity and well-being are a vital part of the lives of children and a child should be protected regardless of race, nationality or creed(信仰).

In 1989 millions of children throughout the world are still innocent victims of war, famine and poverty. Save the Children Fund is still working to raise public awareness and improve conditions.

Save the Children Fund

Name of organization:【46】

Time of foundation:【47】

Founders: a group of【48】

Aims: publicize the problem and help【49】

Those to be protected: needy children【50】

A.意见

B.原则

C.人口

D.欢迎

A.income

B.individual

C.principle

In the United States influenza is one of the ten principle causes of death.

A．Y

B．N

C．NG

A．Their tasty meat.

B．The principle of their defense system against disease.

C．Their solid skin.

D．The principle of their birth modes,

A.rules

B. legislation

C. principle

D. principal