。
They kindly answered my questions.
Literal
Questions [toward-に対しては] kindly answered gave-[past-下さった].
下さった is the past tense of くださる, the honorific form of くれる 'to give/do for me.' 親切に 'kindly' as an adverb. に対しては 'regarding, toward' is formal. The sentence expresses gratitude for receiving help.