the extremely hot weather, we continued having classes．
A. Thanks to
B. In addition to
C. In defence of
D. Regardless of
网友回答
A. Thanks to
B. In addition to
C. In defence of
(答案→)D. Regardless of
解析：短语辨析。 A．由于 B．除……之外 C．保护 D．不顾；不管。句意：不管这极度炎热的天气，我们继续上课。结合语境可知选D为最佳答案。