大型歌舞剧《大北川》是绵阳文化人在“5?12”汶川特大地震发生后献给全国人民的一幕情感盛宴。同时也讴歌了伟大的抗震救灾精神，让人感受到震不倒、折不断、压不垮的民族精神。这一民族精神[ ]

①中 * * 生存与发展的精神支柱

②是以时代精神为核心，以传统文化为载体

③是时代伟大实践的产物

④凸显了中 * * 强大的民族凝聚力和向心力

A．①②③

B．②③④

C．①③④

D．①②④

A 7-year-old boy is hospitalized with cystic fibrosis. To help him manage secretions and avoid respiratory distress, the nurse should （）.

A．perform chest physiotherapy every 4 hours.

B．give pancreatic enzymes as ordered.

C．place the child in an oxygen tent and have oxygen administered continuously.

D．serve a high-calorie diet.