The teacher could tell straight away that he/she got some help from his/her parents
It was obvious to the techer that her/his parents helped her/him with the homework
(1) The teacher could tell straight away that he/she got some help from his/her parents
'could tell straight away' = 「すぐにわかった」「すぐに見抜けた」
'get some help' =「手伝ってもらう」「少し手を貸してもらう」
'parents' = 「親」
「彼・彼女が親に宿題を手伝ってもらったことはすぐに見抜けた」
(2) It was obvious to the teacher that her/his parents helped her/him with the homework
'obvious' ＝「明確」「明らか」「バレバレ」
'obvious to ~' ＝「〜には明らか」
'help ~' ＝「〜を手伝う」
'homework' = 「宿題」
「彼女・彼が親に宿題を手伝ってもらったことは先生には明らかだった」というようなニュアンスの訳出になります。
「素晴らしい作品ができたので〜」と付け足したい場合
(1) Because the final product was amazing, it was obvious to the teacher that her/his parents helped her/him with the homework
'final product' = 「最後に出来上がったもの」「最後の出来栄え」
'amazing' = 「素晴らしい」
日本 
