政府采购合同履行中，采购人需追加合同标的相同的货物、工程或者服务的，在不改变原合同其他条款的前捉下，可以与供应商协商签订补充合同，追加与合同标的相同的货物、工程或服务，所有补充合同的累积增加的、采购金额不得超过原合同采购金额的()。
A. 10％
B. 15％
C. 20％
D. 25％.
查看答案
The following factors tend to promote social change except ______.
A. different kinds of people
B. different points of view
C. different interests
D. different conditions
The major problems with America's railroad system in the mid 19th century lay in ______.
A. limited railroad lines
B. lack of a transcontinental railroad
C. lack of financial support of development
D. poor quality rails and unreliable stopping systems
Woman: Oh, this chicken soup is spoiled. Man: Maybe we ought to tell the waiter about it.
A. He wants to pay the bill.
B. He wants to complain about the soup to the waiter.
C. He thinks the chicken soup is very delicious.
D. He shouldn't eat any chicken soup.
The building of the first transcontinental system ______.
A. relieved the burden of overall railroad system
B. encouraged people to rush for gold in the west
C. attracted many visitors to the construction sites
D. brought about a rapid growth of industry and farming in the west
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