【推荐1】You’d better hold a positive attitude ________life and it’s better to be grateful ________everything you have. （用适当的词填空）

【推荐2】You wouldn't think that a few months of exercise in your teens would be enough ________ the rest of your life, and that's also true for building your vocabulary--you have to keep at it daily, and pretty soon you will find that you have an excellent vocabulary.(用适当的词填空)

【推荐3】It is necessary ________ us to prevent the global warming. (用适当的词填空)

【推荐1】She held an old piece of cloth over them both to keep the rain ________. （用适当的词填空）

【推荐2】__________ a result of the rape of the forests, parts of the country are now short of water. (用适当的词填空)

【推荐3】The new building is________ construction. It will be completed next month. (用适当的词填空)