Question

The fact has worried the people across the world ___________ the earth is becoming warmer and warmer these years.

A．what

B．which

C．that

D．where

Answer 1

：C

：考查同位语从句。同位语从句that the earth is becoming warmer and warmer these years对前面的the fact的内容进行解释说明。That起引导作用，不充当任何成分，没有任何意义。故C正确。