Question

I can lend you the money________ you give it back at the end of three weeks．

1. A.
   in a condition that
2. B.
   on condition that
3. C.
   on one condition
4. D.
   on the condition if

Answer 1

B
on one condition介词短语作状语，意为“规定一个条件”，如：He allowed me to do it on one condition．他有条件地允许我做这件事。on condition that相当于as long as，意为“只要”，引导一个条件状语从句。