Solution:
In this sentence, the subject (the land) is an uncountable noun which is used in the singular sense, so the verb in the third part of the sentence must be singular (has).
Choose the part that has error. Two-fourths of (1) the land (2) have been (3) ploughed. (4)
Choose the part that has error.
Two-fourths of (1) the land (2) have been (3) ploughed. (4)
