1.pin down 確定；使受約束

We should use our secondary forces to pin down several enemy columns.
我們應該用助攻部隊來牽制住敵人的幾個縱隊xXP1k_)DS+Ld。

And that is one problem with those who would wish to include measures of wellbeing in policymaking: it is hard to pin down what they wish to measure.
而這個錯誤恰恰是那些希望能在決策中加入對幸福的考量的政客常犯的：他們希望考量的那個東西，并無明確的定義i~ZyYtGz^U=yw7h。

2.date to 追溯到

We'll change the date to March 28th.
我們將把日期改到3月28日4~s1u@(^B,T!I]|P)r。

Yes you want the date to go perfectly but accept the reality that nothing on this earth is flawless.
是的，你希望約會很完美，但你也得接受現實：這個世界上沒有一樣東西是沒有瑕疵的m|_+9_|G+oc((hFW;(T。