什么叫油鞣革？
参考答案：
油鞣革是含高度不饱和脂肪酸的，氧化时能和裸皮胶原发生化学结合而起鞣制作用的动物油和植物油作鞣料，将皮鞣制成革的方法。
句型转换。
1. She was seen to come out of the library by him (改为主动语态)
He ________ _________ ________ out of the library.
2. When are trees often planted? (改为主动语态)
When ________ people often ________ ________?
3. The League was founded in Guangzhou in 1922. (对画线部分提问)
________ ________ ________ ________ the League ________?
4. Did the students wear the school clothes a lot? (改为被动语态)
________ the school clothes ________ a lot?
5. Kate looked after the baby well yesterday evening. (改为被动语态)
The baby _________ _________ ________ well by Kate yesterday evening.
IDG冷却的循环燃油正常情况下回到哪个油箱（）.
A.中央油箱
B.内侧油箱
C.外侧油箱
D.A+C
