1. cross the river 过河。have difficulty doing something是固定用法，cross做动词“过”“跨”用。2. 不太对，可改为the men found that it is so difficult to cross the river that they have to come back.或the men found that crossing the river is so difficult that they have to come back.3. 在以上例句中find做“发现”用。用法为 主语 find that 谓语从句。...
1. 注意： have difficulty (in) doing sth 结构， in 可以省略2. 正确说法是：The men found it (形式宾语）so difficult to cross the river(具体某一次过河用不定式） that they came back(时态要和found 一致）不懂追问*^__^* ...
