The way people act in private is often different from ________ they act in public．
A.howB.whenC.whichD.what在线课程A
解析：
考查名词性从句。从句谓语介词from之后，是宾语从句，根据主句谓语动词可知从句谓语动词act是不及物动词，根据意思可知引导词作从句的方式状语，选A。难度适中。