冬天燕子飞到南方去了,春天飞回来（中译英）Because the wind blew strongly,we had to stay there for a whole afternoon（把从句转换为简单句,句意不变）

手工翻译：
The swallowes fly to the south in winter and (fly可省略掉）back here in spring.不用过去式，因为描述一种现象。
2. The wind blew so strongly that we had to stay there for a whole afternoon.这就变成简单句了。

冬天燕子飞到南方去了，春天飞回来；The swallow flies went to the south in winter, spring fly back
Because the wind blew intense, we stayed there a whole afternoon

The swallows fly to the south in winter,and they won't back until next spring.
The wind blew strongly.We had to stay there for a whole afternoon.