我上周末想去看你，但我感冒了。

I wanted to visit you last weekend, ___but I caught a cold.

她没有按时提交作业，但她遇到了电脑问题。

She didn't submit the assignment on time, ___but she had computer problems.

他们希望今年夏天出国旅行，但他们负担不起。

They hoped to travel abroad this summer, ___but they couldn't afford it.