The big fire in Shanghai, believed to ______ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there.

1. A.
   have occurred
2. B.
   occur
3. C.
   have been occurring
4. D.
   be occurring

The big fire in Shanghai, believed to ______ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there.

The big fire in Shanghai, believed to ______ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there.

A．have occurred                         B．occur

C．have been occurring                     D．be occurring

The big fire in Shanghai, believed to ________ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there.

A. have occurred 　　 B. occur　　　 C. have been occurring D. be occurring

The big fire in Shanghai, believed to ___ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there．

    A．have occurred                B．occur

    C．have been occurring                      D．be occurring

The big fire in Shanghai, believed to ___ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there．

    A．have occurred                B．occur

    C．have been occurring                      D．be occurring

The big fire in Shanghai, believed to ___ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there．

       A．have occurred                                  B．occur

       C．have been occurring                    D．be occurring

The big fire in Shanghai, believed to ________ due to the burning of construction materials, caused 58 deaths and destroyed all the belongings of the people there.

A. have occurred 　　　 B. occur　 　　　　 C. have been occurring　 D. be occurring