第23题: [单项选择]America will never again have as a nation the spirit of adventure as it ______ before the West was settled. A. could B. did C. would D. was 参考答案:B 答案解析:本题译文:作为一个国家来说,美国将不再具有开拓西部前所具有的那种冒险精神,此题考查助动词。从意义来看,空格应填had,但主句中have是实义动词,为避免重复,可用助动词do替代,即用did替代had,