we promise continuous increase in rural incomes improve the whole people's well-beingA. O

we promise continuous increase in rural incomes improve the whole people's well-being．
A. Only if; we can
B. If only; can we
C. Only if; can we
D. Unless; we can

A. Only if; we can B. If only; can we(答案→)C. Only if; can weD. Unless; we can解析：句意：只有我们承诺不断地增加农村地区人们的收入，我们才能够提高整个人们的幸福感。Only if只有，位于句首时主句要部分倒装。If only要是…该多好啊！故选C.

这下我知道了