Question

chinas great green wall is the governments full-fledged attempt to intentionally increase forest cover through tree planting projects, but scientists have yet to determine ______ effectiveness.
which choice completes the text so that it conforms to the conventions of standard english?
choose 1 answer:
a its
b their
c this
d that

Explanation:

1. The sentence refers to the singular noun phrase "China's Great Green Wall" project. "Its" is the correct singular possessive pronoun to show the effectiveness belongs to this project.
2. "Their" is plural, which does not match the singular subject. "This" and "that" are demonstrative pronouns that do not correctly show possession here.

Answer:

A. Its