许多人对替代疗法的有效性持怀疑态度。

Many people are ___sceptical about the effectiveness of alternative medicine.

董事会从一开始就对提议的合并持怀疑态度。

The board was ___sceptical of the proposed merger from the start.

他不切实际的承诺让选民深感怀疑。

His unrealistic promises left voters deeply ___sceptical.