①
1) 〇
2) have just had lunch
3) 〇
4) 〇 Yes, and he has already gone to bed.
②
1) 〇 2) 〇 3) 〇 4) 〇 5) 〇
③
1) 〇
2) 〇
3) visited(過去) ← when he was(過去) young
4)
5) saw(過去) ← three days ago(3日前):過去
④
1) has just gone home.
2) not prepared for the trip yet.
3) Mr./Ms. Sasaki has taught at this school for eight years.
【別解答】 It has been eight years since Mr./Ms. Sasaki started teaching at this school.
4) I have had a headache since I got up this morning. ※have(持っている):状態を表す動詞のため、通常は進行形にしない。
Give It a Try
[A]
1) 〇
2) 〇
3) but I haven’t finished the report yet.
[B]
1) 〇 + I want to visit there someday. いつか訪れたいと思っています。??
2) I have been playing baseball [for about five years]. ← [ ]期間を追加してみては?
参考にしてください。