孔子人生哲学的主要内容,是（ ）。
A.克己忍让
B.坐忘
C.内省修身
D.虚静无为
正确答案是AC
Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
Humans, like other animals, interact through （ ） behavior by means of signs or symbols used conventionally. (communicate)
