改错。

1. Jim passed the driving test, it surprised everybody in the office. _______

2. Which is known to all, he is the best student. _______

3. It is such a big stone that nobody can lift. _______

4. Our teacher is very strict with us, that does much good to us. _______

5. He will come to see me next July, which he won't be so busy. _______

下列有关物质归类一定正确的是(　　)

①强电解质：氯化氢、氢氧化钡、摩尔盐        　②弱电解质：草酸、纯碱、醋酸铵　③非电解质：液氨、二氧化硫、苯 ④强碱：氢氧化钾、氢氧化钙、氢氧化铁

A．①②③

B．①③

C．①④

D．②③