The correct answer for the question that is being presented above is this one: "b. Mary had heard herself mentioned to Miss Bingley as the most accomplished girl in the neighbourhood; and Catherine and Lydia had been fortunate enough never to be without partners, which was all that they had yet learnt to care for at a ball"
Answer:
a is the right use of 'weather."
All these sentences use the word "so" correctly except "Flies breathe through holes in
<span> their abdomen or thorax, so do bees.</span>" So should either begin a new sentence of be preceded by "and".