在一密闭容器中有A、B、C、D四种物质，一定条件下使之反应，一段时间后，测得反应前后各物质的质量和质量增减如下所示
| 物质 | A | B | C | D |
| 反应前质量/g | 90 | 10 | 28 | 2 |
| 反应后质量/g | 减少 | 增加 | 减少 | 增加 |
A．置换反应
B．分解反应
C．化合反应
D．复分解反应
由表可以发现反应后B物质、D物质的质量增加了，是生成物；A物质、C物质的质量减少了，是反应物．本反应是两种物质反应生成了另外两种物质的反应，有可能是置换反应，也有可能是复分解反应．
故选AD．
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| The great ship, Titanic, sailed for New York from Southampton on April 10th, 1912. She was _1_ 1,316 passengers and a crew of 891. Even _2_ modern standards, the 46,000 ton Titanic was a huge ship. At that time, 3 , she was not only the largest ship that had 4 been built, but was regarded as 5 , for she had sixteen watertight compartments.(轮船的密封舱) Even if two of these were flooded, she _6_ still be able to float. The _7 sinking of this great liner will always be remembered, for she went down on her first voyage with heavy _8_ of life. Four days after setting out, __9_ the Titanic was sailing 10 the icy waters of the North Atlantic, a huge iceberg was suddenly 11 by a lookout. After the alarm had been given, the great ship turned 12 to avoid a direct collision. The Titanic turned just in time, 13 missing the immense wall of ice which rose over 100 feet out of the water beside her. Suddenly, there was a slight trembling sound from 14 , and the captain went down to see what had happened. The noise had been so 15 that no one thought that the ship had been 16 . Below, the captain 17 to his horror that the Titanic was sinking rapidly, for five of her sixteen watertight compartments had already been 18 ! The order to 19 ship was given and hundreds of people jumped into the icy water. As there were not enough lifeboats for 20 , 1,500 lives were lost. | ||||
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