The mother didn’t know_________to blame for the broken glass as it happened while she was out.?

A.who                   B.when                 C.how                   D.what?

The mother didn’t know ____to blame for the broken glass as it happened while she was out.

    A. who    B. when    C. how     D. what

The mother didn’t know _____to blame for the broken glass as it happened while she was out.

The mother didn’t know _____to blame for the broken glass as it happened while she was out.

A．who B．which C． they D．that

The mother didn't know ________ to blame for the broken glass as it happened while she was out.

1. A.
   what
2. B.
   how
3. C.
   when
4. D.
   who