1_____education is the instruction that occurs when the instructor and students are separated by distance or time,or both

Travellers, when ____________ the checks, have to sign the checks in the presence of the bank or service clerks

Data items are added or deleted from the list only at the top of the______．

I don't think the audience would care _________the film is financed or distributed.

Either he or I ______to the airport.

The personal computer or______is the smallest general-purpose computer．

Intelligent animals change their behavior _____ the demands of the situation or environment.

The British Empire was replaced by the British Commonwealth or the Commonwealth of Nations in_____.

It will be a relief over the death of a friend or a relative if the friend or relative dies from ______.

Hurry up, or you ______ catch the train.

Have you ever seen the man in the moon?If you look (11)______ at the moon on some nights. you can see the face of the man in the moon. Some people say that they can see an old man (12) ______ sticks. Others say a girl reading. These pictures are made by the mountains and plains of the moon.Long ago people in England used to tell their children that the moon was (13)______ green cheese. Everyone knows that this is not true. The moon is a large round rock. It is completely (14)______ . There are no trees and plants of any kind on the moon. There are no rivers and seas. There are no living things. It never rains on the moon，and everything is covered with (15)______ . white dust. Not even a (16)______ can be heard on the moon.Where the sun (17)______ on it，the moon is very hot. In the dark，however, it is cold (18) ______ ice. The moon is much smaller than the earth. It does not weigh as (19)______ as the earth. If you (20)______ to the moon，you would weigh six times less than you do. Even a fat man would be able to jump high off the ground.(11)

The ball _____ two or three times before rolling down the slope.