高一文法觀念問題

(1) It has been ten years since I graduated from high school.
應該使用 has been, 今年2013, 十年前你中學畢業 (即是 2003年畢業)
Present perfect tense 接連現在, reference point 是現在, 倒後十年, 十年前 )
如果用 had been (past perfect), 不知道 reference point 是何時, 只知 some time in the past, 句子無言及. 例如講 2005年事件, 前十年, 即是1995

(2) Mr. Wang led a lonely life after all his children moved to the U.S.A.
嚴格來說, USA 前面應該有個 the. 但是有人省略了
the United of States of America, the United States, the US
應該使用 lonely (adjective), lonely life

(3) If you have problems falling asleep...
可以省略了 preposition “in”
trouble 用法跟此一樣
模式 have problem (in) doing something

(4)
是 on the guitar, 不是 with the guitar.你的句子是 Ben 自弹自唱
問題是與這個字 accompany (verb) 有關
accompany (給某人伴奏) = play a musical instrument while someone sings a song or plays a main tune

Peter wants Mary to accompany him on the violin.
The singer was accompanied on the piano by her brother.

(1)has been=present perfect tense=a period of time up to and including the presenthad been=past perfect tense=two incidents, one before the other;had been 10 yrs before the graduated......
(2) the definite article should not be used here.
(3)problems(=troubles) falling asleep; (=verbal adjective.)
(4)on the guitar=on doing something=on the music sound. with Ben's voice.