根据括号中的提示，用名词性从句完成下列各句My question is this.(Which side will yo

根据括号中的提示，用名词性从句完成下列各句My question is this.(Which side will you take?)
Last Sunday he made a promise .(If he was free,he would take me to Beijing.)It is still unknown .(Where was language first used?)This will affect their style of speech.(Where does a person come from?)