问题补充:
The fact has worried many scientists the earth is becoming warmer and warmer these years.
A. what
B. which
C. that
D. whose
答案:
A. what
B. which
(答案→)C. that
D. whose
解析:句意:这些年地球变得越来越暖这个事实困扰着许多科学家们。这里是同位语从句,先行词是fact,同位语从句中不缺少成分,that在从句中不做成分,故选C。