VOA慢速英语:American History: World War II on the Home Front

1.  And they began to prepare for war.

prepare for 为...作准备,计划
例句：She has well prepared for the test.
她对考试已有充分的准备。

2. He remembered how American troops were not ready for that war.

ready for 对...有适合准备,条件等
例句：They were armed to the teeth, ready for any emergency. 
他们已全副武装, 随时准备应急。 

3. And by the time Japan attacked Pearl Harbor, the Americaneconomy was producing millions of guns and other weapons.    
 
millions of 上百万的，许许多多的
例句：Millions of people gave freely in response to the famine appeal. 
千百万人响应救灾呼吁而慷慨解囊.

4. In one picture from the state of North Carolina, a group of men are standing in front of old rubber tires.

in front of 在...的前面
例句：A monument was erected in front of the town hall. 
 一座纪念碑在市政厅前建起。