In this task, you are given two sentences in the English language and your task is to classify them into one of their discourse types. A discourse type is an indicator to classify the given two sentences on the basis of a co-text as well as a relevant context. There are 13 discourse types in total which are 'SINGLE_S_COORD', 'SINGLE_CATAPHORA', 'SINGLE_CONN_INNER', 'SINGLE_APPOSITION', 'SINGLE_VP_COORD', 'SINGLE_CONN_START', 'PAIR_ANAPHORA', 'PAIR_CONN', 'SINGLE_RELATIVE', 'SINGLE_CONN_INNER_ANAPHORA', 'SINGLE_S_COORD_ANAPHORA', 'PAIR_CONN_ANAPHORA' and 'PAIR_NONE'.

Sentence 1:Some evidence suggests that Barbados may have been settled in the second millennium BC , but this is limited to fragments of conch lip adzes found in association with shells that have been radiocarbon - dated to about 1630 BC . Sentence 2:nan
SINGLE_S_COORD

Sentence 1:Bernard reluctantly attempts to call the son of his mother 's employer , with whom he 'd had a sexual encounter as a teenager , while Emory calls a dentist on whom he 'd had a crush while in high school . Sentence 2:nan
SINGLE_CONN_INNER_ANAPHORA

Sentence 1:Carriers of the gene , who are healthy and normal , can be identified by a DNA test . Sentence 2:nan

SINGLE_RELATIVE