1.contribute to 有助于；捐献

例句:The three sons also contribute to the family business.
这3个儿子也为家族事业做出了贡献。

2.in principle 从理论上说

例句:The present world crisis should in principle be analysed from different temporal perspectives.
原则上说来，目前的世界危机应该从不同的时间角度加以分析。

3.What if 假如...会怎么样

例句:What if anything should happen to the child?
万一这孩子出了差错怎么办？

4.in return for 作为...的报答

例句:I'll sell at a discount in return for a speedy sale.
为了尽快售出，我会打折销售。