Humanbehaviorismostlyaproductoflearning________thebehaviorofanimalsdependsmainlyoninstinct.
当x→0时，与根号x等价的无穷小量是（）
Insomeschoolschildrenwhoprefertoreadbooksratherthan________footballbecomesocialoutcasts(被抛弃者).
Ihavebeenstudyinghereforfouryears,bynextsummerI________.
新民主主义社会的基本阶级力量主要有___________。
