The reason why he was late was ___he had taken a wrong bus.

A. because    B. whether    C. because of    D. that

The reason why he was late ________ the meeting was________ he had taken a wrong bus.

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The reason why he was late ________ the meeting was________ he had taken a wrong bus.

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The reason ____he was late was ____he had taken a wrong bus.

The reason ____he was late was ____he had taken a wrong bus.