19．Hundreds of years ago，a Roman army came north from England to make war on Scotland．The Scots，a brave people，loved their country very much．They fought hard to drive the enemy out of Scotland，but there were too many Romans．It looked as if the Romans would win．
One night，the leader of Scots marched his soldiers to the top of a hill．"We will rest here tonight，my men，"he said．"Tomorrow we will fight one more battle．We must win or we will die．"
They were all very tired，so they ate their supper quickly and fell asleep．There were four guards on duty，but they，too，were very tired，and one by one，also fell asleep．
The Romans were not asleep．Quickly they gathered at the foot of the hill．Slowly they climbed up the hillside，taking care not to make a sound．Closer and closer they came to the sleeping Scots．They were almost at the top．A few minutes more，the war would be over．Suddenly，one of them put his foot on a thistle（蓟）．He cried out and his sudden cry woke the Scots．In a moment，they were on their feet and ready for battle．The fighting was hard but it did not last long．The Scots wiped out the Romans and saved their country．
The thistle is not a beautiful plant．It has sharp needles all over it．Few people like it．But the people of Scotland liked it so much that they made it their national flower．
21．Hundreds of years ago there was a war betweenB．
A．Roman army and North England
B．Roman army and the Scots
C．England and Scots
D．a brave people and the Scots
22．"We must win or we will die．"What the leader of the Scots said meansD．
A．they were sure to win
B．they couldn't escape from death
C．they would win and then they would die
D．they must try hard to win，otherwise they would be killed
23．The Romans climbed up the hill quietly becauseA．
A．they didn't want to wake the Scots
B．they wanted to reach the top
C．they wanted to catch the four guards first
D．they were afraid of the sharp needles of the thistle
24．What's the main idea of the passage？D
A．The thistle is a beautiful plant
B．The people of Scotland like the thistle
C．The Romans are a brave people
D．The thistle helped the Scots win the battle．
