9. Several important legal questions arose in the contract negotiations.
在合同談判中出現了一些重要的法律問題。
還能這樣說：
There exist some critical legal questions in the contract negotiations.
Some significant legal questions emerge from the contract negotiations.
應用解析：
legal affairs 法律事務；
legal adviser 法律顧問；
take a legal action 提起訴訟

10. The talks were hung up for a week.
談判中止了一個星期。
還能這樣說：
The talks had terminated for a week.
The talks had suspended for seven days.
應用解析：
Hang it (all) ! 見鬼！該死！豈有此理！（表示反對、不耐煩、驚異等）；
hang it out 拖延，故意拖拉

11. We are responsible to replace the defective ones.
我們保換質量不合格的產品。
還能這樣說：
We promise to change the inferior goods.
We guarantee that the poor-quality commodity can be changed.
應用解析：
replace指代替某人或取代已經失去的、毀壞的或用壞的東西；
supersede系正式用語，指用更好的、最新的東西替換過時的或無用的東西；
supplant指以武力、欺騙等手段替代原來的人或其職位。

12. The negotiations broke down because neither side would compromise.
由于雙方都不愿讓步，所以談判破裂了。
還能這樣說：
As neither side would give in, the talks broke down.
Since both sides didn't want to make a concession, the negotiations came to nothing.
諺語：
There is much to be said on both sides.
公說公有理，婆說婆有理。