下列各句中，没有语病的一句是（     ）

This problem is said_____ three times atthe meeting. However, they haven’t arrived at a conclusion now.

Do you regret paying 500 dollars for your necklace? –No, I would gladly pay__________ for it.

known to all language learners, newly learnt words will soon be forgotten unless ______.

The word “ungelivable” based on Chinese, which has become a big hit online very quickly, ______ a message that Chinese can also serve as an addition to English vocabulary.