Hundreds of years ago, a Roman army came north from England to make war on Scotland. The Scots, a br

　　D. the Scots defeated the Romans
67. The Scots made thistle their national flower because thistle ____ .
　　A. is lovely, though not beautiful
　　B. gave them happiness
　　C. is a kind of useful plant
　　D. helped the Scots in wiping out the Romans