Some researchers have discovered that chimpanzees have a hallmark of human culture.

A．Fear helps us to be careful about our surroundings.
B．Anger may stimulate us to make greater efforts.
C．Happiness inspires us to continue what we are doing.
D．Anger tends to do us more harm than good.

A．we must control our emotions in daily life
B．emotions play a more important part than we realize
C．positive emotions such as love and joy are good for us
D．negative emotions such as hate and sadness prevent us from rational thinking