China-America relation is much more complicated than you can think, no single word such as 'love' or 'hate'can describe it.
In the WW2 China alone were dealing with more than 4 million Japanese army, which gives the America considerable latitude to focus in the Eroup warfield.
During the WW2 America gived much more assistance to Soveit, need Soviet say thanks? They were saving each other!
Of course Chinese people are grateful to all the people and nations who helped China,Not only those brave American and Soviet pilotes who helped China during the Anti- Japan war are still remembered and hornored by Chinese nowadays,
an Indian doctor too is on the Chinese history text-book.
BTW, when Japan started to invade China in 1931, and until Jpanese attacked the pearl harbor in 1941, the Americans were continuously exports oil and steel to Japn. which was made to weapons to kill Chinese.