问题补充：
--- Do you know ?
--- Sorry, I have no idea. I’ll search the Internet to find it out.
A. where will the next Expo be held
B. when will the next Expo start
C. what will the next Expo be held for
D. how many countries will take part in the next Expo
答案：
A. where will the next Expo be held
B. when will the next Expo start
C. what will the next Expo be held for
(答案→)D. how many countries will take part in the next Expo
解析：宾语从句中一般为陈述语序，但是当疑问词充当从句主语时，貌似倒装语序，因此宾语从句的判断一定要结合句子成分来判断。选项A中疑问词为逻辑地点状语，后面句子应倒装。选项B中疑问词为逻辑时间状语，后面句子应倒装。选项C疑问词为动词逻辑宾语，句子也该倒装。选项D疑问词为从句主语，则貌似倒装，实为陈述语序，故选D。
