1、last①持续、继续…,如：
The flowers show lasted a week.花展持续了一周.
②支持、保持、耐久,如：
How long will this battery last?
2、keep ①保持、保留(存),如：
He may keep the book until you come back.
②保有
You can keep it if you like it.
③饲养(动物)、抚养(家属)、雇佣(仆人)、收留(住宿者),如：
She has kept the cat these ten years.
3、continue①(continue是不间断的继续,而last 是中断、间断时又继续,如：
This road continued for miles.
②The rain continued three days.
这道题的题意是晚间新闻只有半个小时的播出时间 所以选D