It was in the lab ________ was taken charge of by Prof. Harris ________ they did the experiment.

1. A.
   which, that
2. B.
   that, what
3. C.
   whom, that
4. D.
   which, where

It was in the lab ____ was taken charge of by Prof. Harris ____ they did the experiment.

A. which; where       B. that; where     C. that; which       D. which;, that

It was in the lab ________was taken charge of by Prof. Harris ________they did the experiment.

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It was in the lab ________ was taken charge of by Prof. Harris ________ they did the experiment.

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