I have often since thought, when I have seen people grumbling at home, or finding fault or quarrelling with their brothers and sisters or parents, let them go away and get knocked and kicked about the world, and they will have good reason to value their own quiet home as they ought. (A Voyage round the World by W.H.G. Kingston）
動画の後半部分でリスニング用音声が流れます。
英文を前から読んでいくために、語句のかたまりを作ります。こんな具合に課題文をスラッシュ（斜め線）で区切ります（スラッシュリーディング）。語句のかたまりを意識すると、リスニングで英語の意味をつかむのが楽になります。
I have often since thought,／（接続詞の前）when I have seen people grumbling at home,／（接続詞の前）or finding fault or quarrelling with their brothers and sisters or parents,／（コンマの後）let them go away and get knocked and kicked about the world,／（接続詞の前）and they will have good reason／（不定詞の前）to value their own quiet home as they ought.
語句のかたまりを前から訳していきます。
I have often since thought,
私はそれ以来、しばしば考えている
when I have seen people grumbling at home,
人々が家で不平を言っているのを目にしたとき
or finding fault or quarrelling with their brothers and sisters or parents,
あるいは兄弟姉妹や両親のあら探しをしたり、口論したりしているのを
let them go away and get knocked and kicked about the world,
彼らを家の外に放り出し、外の世界で苦労させなさい
and they will have good reason
そうすれば十分な理由を見出すだろう
to value their own quiet home as they ought.
きちんと自分の静かな家庭を大事にすべきだという
I have often since thought, when I have seen people grumbling at home, or finding fault or quarrelling with their brothers and sisters or parents, let them go away and get knocked and kicked about the world, and they will have good reason to value their own quiet home as they ought.
finding fault or quarrelling with their brothers and sisters or parents→ with〜 は finding fault と quarrelling の両方にかかっています。find fault with = あら探しをする／quarrel with = 口論する
as they ought→ as they ought（to value）=本来、大事にすべきであるように
私はそれ以来、人々が家で不平を言ったり、兄弟姉妹や両親のあら探しをしたり、口論したりしているのを目にするとき、しばしば考えている。彼らを家の外に放り出し、外の世界で苦労させれば、きちんと自分の静かな家庭を大事にすべきだという十分な理由を見出すだろう、と。
今回の課題文には、「命令文＋and〜」（―しなさい、そうすれば〜）が使われています。文章の中に組み込まれているためにわかりにくくなっているので、見落とさないようにしましょう。
I have often since thought, when I have seen people grumbling at home, or finding fault or quarrelling with their brothers and sisters or parents, let them go away and get knocked and kicked about the world, and they will have good reason to value their own quiet home as they ought.
let them go away and get knocked and kicked about the world, and they will have good reason to value their own quiet home as they ought→ 彼らを家の外に放り出し、外の世界で苦労させなさい。そうすれば、きちんと自分の静かな家庭を大事にすべきだという十分な理由を見出すだろう
