Grammar

Present Perfect Continuous Tense (現在完成進行式)
1. 當一個動作於過去發生，持續到現在，並有可能會繼續發生至將來
--- Mr. Chan owns a garage. He has been repairing cars for a living since he left school.
--- Winkie has been writing letter all morning. So far she has written three letters.
2. 來表達一個比較臨時，較短暫的動作
--- You have been working hard recently. You should take care of your health

Present Continuous Tense （現在進行式）
可以運用的副詞： Now, Still, At the moment, At present, always, constantly, continually, now,at this moment, etc)
1. 表示一個與說話時同步進行的動作
--- Your father is working, don't disturb him.
2. 表示一個發生時間比現在相差不遠的動作
--- I see your brother is reading the classified ads.
3. 表示一個時常重復又惹人煩厭的動作或事情：
--- Your sister is always talking in class. You should do something about it.
4. 表示一個正在轉變中的事件或計劃了而將進行的事情：
--- It is getting dark, we would better leave.
--- It is going to rain.

參考網頁:http://www.crazyhill.com/hung/english/tense.htm

1) I (could) see 的could係過去式, 我見到James正在puzzled expression解答中,由於動作進行中,所以用was having
2) as不係解during - during要用perfect tense,而係 解because/since/as/while/when 等,句子中的as解當
as we (came) up 的came係過去式,所以只用一個答案(were admiring)
- 表示一個發生時間比現在相差不遠的動作所以用were admiring

present perfect係一d你之前開始做宜你到宜家仲做近既就用佢...
continuous就係拍宜家做近既野(可能係岩岩先開始做)
你見到for(a time)/since(a time)就係perfect
見到now,at this moment就係continuous
1)後面有ing form
2)as係解during咁解,姐係進行中