Americans are nervous ____________ the prospect of a nuclear-armed Iran, but also worry __________ the ability of the United States and the United Nations to deal with the situation.

1. A.
   about; about
2. B.
   to; about
3. C.
   for; about
4. D.
   for; for

Americans are nervous ____________ the prospect of a nuclear-armed Iran, but also worry

__________ the ability of the United States and the United Nations to deal with the situation.

 A．about; about       B．to; about      C．for; about     D．for; for