【推荐1】He looked ______ so I repeated the ______ question. He ______ over the problem for ages before the light suddenly dawned. (puzzle) (所给词的适当形式填空)

【推荐1】His speech won the__________(applaud)of the audience. （所给词的适当形式填空）

【推荐2】Scottish National Portrait(肖像画)Gallery presents a series of _______ (lecture) for the general public. (所给词的适当形式填空)

【推荐3】Try not let a calm discussion turn into a heated ______ (argue). （所给词的适当形式填空）

【推荐1】Mr Bissell skillfully organizes historical insights and cultural ________ (refer), making his tale a well-rounded picture of Uzbekistan, seen from Western eyes.(所给词的适当形式填空)

【推荐2】This painting represents the first ________ (settle) arriving in America. (用所给词的适当形式填空)

【推荐3】Our environment is suffering due to the ________(explode) of population and unsustainable development. (所给词的适当形式填空)