—Alice, you look puzzled．Haven’t you understood it?

—Yes. I        of another problem just now.

A．have thought        B．am thinking           C．had thought               D．was thinking

—Alice, you look puzzled．Haven’t you understood it? 

—Yes．I _____of another problem just now．

1. A.
   had thought
2. B.
   have thought
3. C.
   thought
4. D.
   was thinking

—Alice, you look puzzled．Haven’t you understood it?
—Yes．I _____of another problem just now．

1. A.
   had thought
2. B.
   have thought
3. C.
   thought
4. D.
   was thinking

—Alice, you look puzzled．Haven’t you understood it?

    —Yes．I       _of another problem just now．

A．had thought           B．have thought        C．thought               D．was thinking

．—Alice, you look puzzled．Haven’t you understood it?

    —Yes．I       _of another problem just now．

A．had thought           B．have thought        C．thought               D．was thinking

（2010·重庆模拟）—Alice, you look puzzled．Haven’t you understood it?

 —Yes．I _____of another problem just now． 

A．had thought                B．have thought       C．thought           D．was thinking

（2010·重庆模拟）—Alice, you look puzzled．Haven’t you understood it?

 —Yes．I _____of another problem just now． 

A．had thought    B．have thought        C．thought        D．was thinking

（2010·重庆模拟）—Alice, you look puzzled．Haven’t you understood it?
—Yes．I _____of another problem just now．