【题目】Theresa May asked Russian officials to explain ________ they were responsible for the chemical attack in Salisbury, England.
A. if B. that
C. which D. where
在线课程【答案】A
【解析】考查宾语从句连接词。句意：特蕾莎·梅要求俄罗斯官员解释他们是否应对英格兰索尔兹伯里的化学袭击负责。该句是宾语从句，根据句意可知，这里指的是是否应该对其负责，所以需用连接词if，故选A。