Knowing _____, as a matter of fact, one shouldn’t know is a terrible thing．

Knowing _____, as a matter of fact, one shouldn’t know is a terrible thing．

1. A.
   whether
2. B.
   that
3. C.
   what
4. D.
   when

Knowing _____, as a matter of fact, one shouldn’t know is a terrible thing．

A．whether                  B．that                        C．what                       D．when

Knowing _____, as a matter of fact, one shouldn’t know is a terrible thing．

Knowing ________, as a matter of fact, one shouldn't know is a terrible thing.

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