The passenger was very impolite to the conductor, ____ , of course , made things even worse．

A．who          B．whom            C．what       D．which

The passenger was very impolite to the conductor, ____ , of course , made things even worse.

The passenger was very impolite to the conductor, ____ , of course , made things even worse.

That passenger was very impolite to the conductor, ______, of course, made things even worse.

 That passenger was very impolite to the conductor, ______, of course, made things even worse.

A．who             B．which            C．what             D．that

That passenger was very impolite to the conductor, ________ of course made things even worse .

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That passenger was very impolite to the conductor, ________ of course, made things even worse.

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