---Could you tell me the_______of making such tasty cakes?
---Well，I just follow the instructions in the cookbook.
A：time
B：method
C：cost
D：menu
Fire is very dangerous. It can ____people. We ____be careful with fire. We mustn't play near fires. We mustn't play with matches. We mustn't ____in the forest. When we see a fire, we must go outside ____，but ____use the lift.
观察菜青虫是否取食十字花科植物要从虫卵开始隔离饲养，这是因为（ ）
