I think the talk given by the old scientist is ______ worth ______.

A. very, to listen　B. well, listening　C. very, to listen to　D. well, listening to

I think the talk given by the old scientist is ______ worth ______.

1. A.
   very, to listen
2. B.
   well, listening
3. C.
   very, to listen to
4. D.
   well, listening to

I think the talk given by the old scientist is ______ worth ______.

I think the talk given by the old scientist is ______ worth ______.