植物病害防治的主要途径有哪些？
参考答案：
减少初始菌量、降低流行速度、同时作用于两者来阻碍病害流行
单句改错。
( ) 1. Would you like any mooncakes? No，thanks.
A B C D
( ) 2. We have a lots of homework to do every day.
( ) 3. Simon likes chocolates eggs very much.
( ) 4. Christmas is on December 25th on winter.
( ) 5. People give children sweets with a treat.
发电机在并列过程中，当发电机电压与系统电压相位不一致时，将产生冲击电流，此冲击电流最大值发生在两个电压相差为（）时。
A、0º
B、90º
C、180º
D、100º
