No excerto "The extraterrestrials' home planet is situated in a solar system with three suns, hence their name in the English translation of the book - the Trisolarans. This three-sun system can be highly unstable, making conditions difficult for life, hence the desire to travel across the Universe in order to inhabit our relatively stable Solar System.", retirado do 5º parágrafo, o termo HENCE pode ser substituído em ambas as ocorrências, sem alteração de sentido, por
Resolução passo a passo com explicação detalhada de cada alternativa...