He declined to speculate on who might be behind the attack.

But she declined to speculate on how many there might be.

He declined to speculate on how many may have died.

American officials declined to speculate on how they might respond.

But he declined to speculate about its possible role in human behavior.

He also declined to speculate about who might be responsible for the attack.

Most, however, declined to speculate on why the Governor decided against a national campaign.

Officials of both companies declined to speculate on what future projects were being considered.

He declined to speculate on the source of the money.

But yesterday he, too, declined to speculate as to any changes in the company.