The soil that had been converted to flowers was on its way .A. grow; offB. growing; out

问题补充：

The soil that had been converted to flowers was on its way .

A. grow; off

B. growing; out

C. grow; out

D. growing; by

答案：

A. grow; off

(答案→)B. growing; out

C. grow; out

D. growing; by

解析：convert to转而变为，to为介词，因此用growing；out耗尽。