Q1. The implications of an unprecedented rate of _______________ are very serious.
A Flooding and droughts
B Global warming Correct
C Ecological disaster
D Kyoto summit
Explanation
The blank needs a phrase that can naturally follow “an unprecedented rate of” and also fit the passage context. “Global warming” works because a rate of warming can be unprecedented and its implications can be serious. Flooding and droughts are consequences, not something normally described as a single rate in this sentence. Ecological disaster is an outcome rather than the measured process being discussed. Kyoto summit is an event, so it cannot grammatically or logically fill the blank.