以下哪句話的獨立主格用的是對的?
1.Jack is running fast ,with his dog left behind.
2.Jack is running fast ,with his dog being left behind.
3.如果上面兩句的with都省略還對嗎?
請簡要說明理由,
***注意：請先回答第1、2句哪句對或者都對，簡要說明理由后再回答第3個問題。