用性引诱剂诱杀农业上蛾蝶类害虫利用的原理是( )
A:昆虫的取食行为
B:昆虫之间的通讯
C:昆虫的学习行为
D:昆虫的迁徙行为
下列函数中,既是偶函数又在区间(0,+∞)上单调递减的是( )
School students _____ smoke because it is bad for their health and it is against the law.