他对照着答案改错。
He corrects mistakes against the answer key.
对照
to contrast; to compare; to place side by side for comparison (as parallel texts)
Watch it being written
Every character draws itself, stroke by stroke. Then grab the brush: trace it yourself and hear the word when you finish.
对
照
Nice writing!
Build with these blocks
Chinese words snap together like bricks. Every word below shares a character with this one, so you are already halfway to knowing it.
对
See it in sentences
你对照过原文吗？
Have you compared it with the original?