Translation:High school homework is hard.
Yes, but "High school assignments are hard." is nevertheless rejected. Just reported it.
Oddly, the suggested answer is "High school assignment is very hard.", which is not valid English.
"The high school assignments are hard." is also rejected and results in a suggestion to use "The High school assignment is very hard.", which uses improper capitalization (of "high").
puh-lease! I spend more time on this forum than I do ATTEMPTING (futilely) to test out of modules that are way too easy for me in the first place. I feel like I should be getting paid at this point. Accept "High school assignments are hard." so we can get on with our lives.
You don't, as far as I know. We are used to explicitly getting that information in English and other European languages. In Chinese, you don't necessarily give or get that information. It's similar to verbs in Chinese, since there is no conjugation, if the sentence doesn't have an explicit time setting phrase, you have no idea of the time period.