Hello, I am Yoshi from NILS Japanese language school.
[N1 は N2 が adjective]
This sentence pattern is used to describe an attribute of a thing or a person. The topic of the sentence is denoted by the particle は. N1 is the topic of the sentence. N2 is the subject of the adjective’s description.
(Example)
福岡は　食べ物が　おいしいです。　　　Food is tasty in Fukuoka.
マリアさんは　髪（かみ）が　長いです。　　　Maria has long hair.

[どうやって]
どうやって is used to ask the way or the method of doing something. To answer such a question, the pattern learned in [V て-form、～] we learned in Lesson 16-(1).
(Example)
大学まで　どうやって　行きますか。
—京都駅から　バスに　乗って、　大学前で　降ります。
How do you go to your university?
—I take a bus from Kyoto Station and get off at Daigaku-mae.

[どの N]
You learned in Lesson 2 that この, その and あの modify nouns. The interrogative word used in this system is どの. どの is used to ask the listener to define one among more than two which are concretely presented.
(Example)
サントスさんは　どの　人　ですか。
—あの　背が　高くて、　髪が　黒い　人です。
Which one is Mr. Santos?
—That tall man with black hair is.

October 19th News, from NILS Japanese language school.