—You missed the train? —Yes. I had gone by taxi.A. If onlyB. Only ifC. So long asD. as lon

问题补充：

—You missed the train?

—Yes. I had gone by taxi.

A. If only

B. Only if

C. So long as

D. as long as

答案：

(答案→)A. If only

B. Only if

C. So long as

D. as long as

解析：考查状语从句的引导词。If only 要是……就好了，Only if 只要，So/ as long as只要，句意：你错过了火车？是的，要是我乘出租车去就好了。所以选A。