下列化学反应中，属于化合反应的是（ ）
A．H2CO3═H2O+CO2↑
B．CaO+H2O═Ca（OH）2
C．2Al+3CuSO4═3Cu+Al2（SO4）3
D．NaOH+HCl═NaCl+H2O
A、反应物是一种，生成物是两种，属于分解反应．
B、反应物是两种，生成物是一种，属于化合反应．
C、反应物和生成物都是两种，并且都是一种单质和一种化合物，属于置换反应．
D、反应物和生成物都是两种，并且都是化合物，且是两种物质互相交换成分的反应，属于复分解反应．
故选B．
| 先阅读短文，在横线上写出各单词的正确形式，单词的第一个字母已给出。 |
| One day Harvey's wife was cleaning out a cupboard. "Look at all these umbrellas," Harvey's wife said to him. "There are eight and they all b 1 ." "I'll take them all to the umbrella shop and have them repaired," Harvey said. "They are too good to t 2 away." Harvey took the eight umbrellas to the shop and l 3 them there. The shopkeeper said, "They'll be r 4 tomorrow." That evening Harvey went home from the office by bus as he u 5 did. He sat next to an old woman. She had an umbrella on the floor between the s 6 . When the bus reached his stop, he picked up her umbrella and stood up. "Hey!" the woman said, "That umbrella b 7 to me." "I'm so sorry." Harvey said, giving it to her. "Please excuse me for taking your umbrella by m 8 ." The next day he collected the umbrellas from the umbrella shop and got on the bus. As he sat down, a v 9 behind said, "You have certainly had a s 10 day!" He turned around and saw the woman whose umbrella he had almost taken the day before. |