We need to conduct extensive background research on the firms from（）we received bids.
 

A:which B:where C:that D:when

We need to conduct extensive background research on the firms from （） we received bids.

A:which B:where C:that D:when

We need to conduct extensive background research on the firms from （） we received bids.

A:which B:where C:that D:when

We need to conduct extensive background research on the firms from（）we received bids.
 

A:which B:where C:that D:when

Extensive use of （） communication is most likely to aid in solving complex problems.

A:verbal B:written C:formal D:non-verbal

Extensive use of______communication is most likely to aid in solving complex problems．

A:verbal B:written C:formal D:non-verbal