I could just make out that he had a book as well as a knife in his hand, and was still wondering how anything so incongruous had come in their possession when the kneeling figure rose once more to his feet and the whole party began to move together towards the house. (Treasure Island by Robert Louis Stevenson）
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 could just make out／（接続詞の前）that he had a book as well as a knife in his hand,／（接続詞の前）and was still wondering／（疑問詞の前）how anything so incongruous had come in their possession／（接続詞の前）when the kneeling figure rose once more to his feet／（接続詞の前）and the whole party began to move together towards the house.
語句のかたまりを前から訳していきます。
I could just make out
私はかろうじて見分けられた
that he had a book as well as a knife in his hand,
彼が手にナイフだけでなく本も持っていると
and was still wondering
それでも、〜かと不思議に思っていた
how anything so incongruous had come in their possession
そんなに不釣り合いなものがどのようにして彼らの手に渡ったのか
when the kneeling figure rose once more to his feet
（そのとき）ひざまずいていた人物が再び立ち上がった
and the whole party began to move together towards the house.
そして、グループ全体が家に向かって一緒に移動しはじめた
彼が手にナイフだけでなく本も持っているのが、かろうじて見分けられた。それでも、そんなに不釣り合いなものがどのようにして彼らの手に渡ったのか、私が不思議に思っていると、ひざまずいていた人物が再び立ち上がり、グループ全体が家に向かって一緒に移動しはじめた。
make out = （かろうじて）見分ける、聞き分ける
例：I could make out that someone was moving inside the house.→ 誰かが家の中で動いているのが見分けられた。
課題文中の表現：I could just make out that he had a book as well as a knife in his hand→ 彼が手にナイフだけでなく本も持っているのが、かろうじて見分けられた
