i know one correct answer,is DDCAA?
In English ‘an’ is used when it is before a word with a vowel sound. ‘Are you an Australian?’ While Perth is a major city in Australia, it is also a city in the state of Washington, which is in the northwestern part of the United States.
One of your answers is incorrect.
Hmm…
Two of your answers are definitely right. One is definitely wrong. The other two are OK as English, but I think your teacher may have different answers for them.
By the way, one of Johnny LA’s corrections has also changed the “right” answer for that question.
Really? Which one?
it’s my mistake,my english teacher said that Washington has no domicile. is it ture?
I don’t understand your use of the word ‘domicile’, which means ‘home’ or ‘residence’. Also, a statement that is not false is true; not ‘ture’. 
Question 3. Your addition of “is” makes a great deal of difference to it.
Your version of #3, Johnny L.A. Your addition of “is” changes the question.
As icekimi presented it, there is a correct answer, if we only add the bolded “a” below:
This is more of a geography question, but the distinction is between Washington State, in the northwest of the USA, and Washington D. C., the capital city of the USA, on the east coast, which isn’t in any of the 50 states.
Aha. I see. But the correct answer, if ‘a’ is left out, is still not grammatical. So the correct answer depends upon how the question is corrected. Since my correction was the insertion of two words and yours is the addition onf one word, I think yours is the better option.
Sorry,My English is too bad.i wanted to say there is no person live in Washington.is it ture?
The first one. Although your modification is grammatically correct, given the context of the original (granted questionable) grammer (specifically the object of the preposition on/of) the correct answer is different either way. Although I do agree with your modification because I cannot imagine anyone intentionally teaching the correct way to use bad english.
Also, your observation that #4 has two right answers is incorrect, there is only one correct answer due to the comma, without the comma the other one is correct.
icekimi, I don’t know what your options are for an english teacher, but if you have another option you might wish to pursue that one.
You are correct. I was being lazy when I responded. :o
Washington State - population 5,894,121.
Washington D. C. - population 553,523.
No, it’s not true. 
Washington State - population 5,894,121.
Washington D. C. - population 553,523.
No, it’s not true.
i will ask my teacher tomorrow.
It’s too late …
I think I mast go to bad now…
Thank you!every one
It’s very kind of you .
I think all your answers are very useful…
See you
Oh,bed isn’t bad…