instruction:
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'.
question:
Sentence 1:The seventh wall contained the Citadel with the white Tower of Ecthelion , which was 300 ft ( 91 m ) high , so that its pinnacle was one thousand feet ( 300 m ) above the plain . Sentence 2:nan
answer:
SINGLE_RELATIVE


question:
Sentence 1:What triggers germination is unknown , and seedlings have also arisen from areas disturbed by sand mining , sometimes growing in higher concentrations than before the disturbance . Sentence 2:nan
answer:
SINGLE_S_COORD


question:
Sentence 1:Sakhr was wounded in the process and died of his wounds a year later . Sentence 2:nan
answer:

SINGLE_VP_COORD