The film Let the Bullets Fly_____ a great success and brought in a large profit to the cinema

依次填入下列各句横线处的词语，最恰当的一组是（ ）①逐步推广使用清洁的可再生能源，减少使用污染环境的能源，是 环境恶化的正确选择。②国庆长假期间，凡在本公司购买商品满1000元者，本公司将 价值100元的礼品券。③作者科尔曼年轻气盛，观点鲜明，但常常论据不足或论证不周，______显得犀利有余，老练不够。④连学好母语都需要花大力气，下苦功夫，_______学习外语呢

Is_______ necessary to learn anotherlanguage? — I think so.

What we have been doing may not do us any good, but ______ it will benefit us or others,we’ll stick it out

The boy with the two dogs _____ when the earthquakerocked the city