导致肉类腐败变质的主要原因：（）和（）。
参考答案：微生物生长繁殖；酶活性
句型转换。
1. Why are you doing that?(改为同义句)
_____ are you doing that_____?
2.You'll be the champion in 7hours.(就画线部分提问)
_____will you be the champion?
3. This is such a beautiful piece of music.(改为同义句)
This is_____piece of music.
4.The blue whale weighs more than 26 tons.(就画线部分提问)
_____the blue whale _____?
10，10，8，4，( )
A．4
B．2
C．-2
D．-4
