In Chinese families, people won't start dinner ________ the elders take their seats.
句意：在中国家庭里，人们直到老人们坐下才开始吃饭。
考查连词。after在……之后；when在……时候；because因为；until直到。根据“won't start dinner”可知句子使用“not…until…”的结构，此处表示“直到老人们坐下才开始吃饭”，用until。故选D。
In Chinese families, people won't start dinner ________ the elders take their seats.
Swimming is, of course, interesting. But ______ we plan to go swimming, being safe must come first.
The clever boy called 120 _______ his mother fell down in the kitchen.
—I'm afraid we can't work out the math problem________the teacher helps us.
—That's true. It's too difficult.
I don’t like Sun Cinema ________ it has bad service.
Check what you have written _______ you hand in your application form.
We still know little about the Moon _____ men have landed on it.
The movie Nezha is_______ educational ____ I want to see it again.
You can surf the Internet ______ you want to know more about the 2020 World Middle School Games.
—How time flies! The middle school life is coming to an end.
—Yes. We have to say goodbye, ________ our friendship will last forever.
