"they are"的问句是 "Are they...？"。例如：
1. Are they your books？
2. Are they playing basketball on the playground？
3. Are they custom officers？
4. Are they Russian？
"they are"的问句是 "Are they...？"。例如：
1. Are they your books？
2. Are they playing basketball on the playground？
3. Are they custom officers？
4. Are they Russian？