they were here now we would be able to celebrate their wedding anniversary.A. Only ifB.

问题补充：

they were here now, we would be able to celebrate their wedding anniversary.

A. Only if

B. If only

C. Because

D. When

答案：

A. Only if

(答案→)B. If only

C. Because

D. When

解析：考查连词。 they were here now,用的是和现在情况相反的虚拟语气，四个选项中只有If only后面跟虚拟语。所以选B。