How long is the holiday?holiday不是可数名词吗?为什么不用复数?

How long is the forever? HOW long is the marathon? How long is the desk?How tall is the building? How long is the river同意句 how long is the way home when the winter is coming,how long the spring? How long is it? How long is your what is the capital of china how big is beijing how long is the great wall How long is the Great Wall How wide is the Great Wall How old is the Great Wall how long is the great wall?怎么回答 How long the river is it'怎么用英语翻译 How long is the Chang Jiang River?我要回答。 long the road is前面应该填how还是what 连词成句：long ,ruler ,the ,how ,is Happiness is how long to wait for the next stop 怎样回答How long is the Summer palace? How long is each side of the square?的中文.