In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.

Article: There are many differences between British English and American English.I used to teach a course about the differences between the two.We speak English on both sides of the Atlantic Ocean but we have many differences in our common language.We have examples of the same words having very d ifferent meanings,differing spellings of the same words as well as completely different words for the same things.Here are some examples. A cookie in the US is called a biscuit in the UK.A biscuit in the US is a small cake in the UK.Crisps in the UK,are known as chips,but we British people eat a plate of chips that you call fries in the US.In the UK,a pie can be made from either meat or fruit,while in the US pies are normally made from fruit;pot pies are made from meat.Most things are measured in grams and kilograms in the US,not pounds and ounces. One very obvious difference is the side of the road we each choose to drive on.Petrol in the UK is gas in the US.The place where we fill up our cars,in the UK,is a garage;while in the US,it's a gas station.The term garage is also used as a place to store your car next to or close by your house.In the UK we call a lorry what is known as a truck in the US. An elevator in the US is called a lift here,and the first floor in the US,is calle d the ground floor here,so many visitors get off on the wrong floor in British hotels. I could continue with this. There are countless examples of differences within our one shared language.With so many differences,no wonder it's hard to understand each other well.
Answer: vocabulary
The passage is mainly about the differences between British English and American English in _ .