he was able to set up his camp very close to the volcano中close to 做什么成分?close to做介词?形容词?

he was able to set up his camp very close to the volcano中close to 做什么成分?close to做介词?形容词?
he was able to set up his camp very close to the volcano中close to 做什么成分?
close to做介词?形容词?

he was able to set up his camp very close to the volcano中close to 做什么成分?close to做介词?形容词?
close to 是副词短语,做状语,表达 set up his camp 的位置.