1．(2020·新高考山东卷)The 80，000 objects collected by Sir Hans Sloane，for example，________(form)the core collection of the British Museum which opened in 1759.
解析： 考查动词的时态。根据上文内容以及时间状语 in 1759可知，应用一般过去时。
答案： formed
2．(2020·全国卷Ⅲ)When he asked the villagers on the banks of the river where he could find the legendary (传奇的)artist，they smiled and ________(point)down the river.
解析： 考查时态。空处与smiled构成并列谓语，故用一般过去时。
答案： pointed
3．(2020·浙江卷7月)By about 6000 BC，people ________(discover)the best crops to grow and animals to raise.
解析： 考查动词的时态。根据时间状语By about 6000 BC可知，句子谓语动词用过去完成时，故填had discovered。
答案： had discovered
