单选题
1.Some people who are very intelligent and successful in their fields find _______ difficult to succeed in language learning.
A.which
B.how
C.that
D.it
正确答案：D
答案解析：本题考查it作形式宾语的用法。it在这里做形式宾语。句意为：一些在自己领域才智过人并且非常成功的人发现，在语言学习上取得成功是很困难的。