1.both ...and (use后加both..and連接的賓語,不可能use or/and,除非后面也是動(dòng)詞)
2.was picked 從in 1957可知是過去時(shí),他被選為,要用被動(dòng).
3.hadn't been 虛擬語氣用法,與過去事實(shí)相反 if從句had done,主句would/could/...have done;與現(xiàn)在事實(shí)相反：If ..did(be動(dòng)詞用were),主句...would/could...do; 與將來事實(shí)相反：If...did/should do / were to do,主句...would/could...do.
4.such a (such a +形容詞+單數(shù)、such +形容詞+復(fù)數(shù)/不可數(shù);so +形容詞+a +單數(shù))