1.(2018·全国卷Ⅱ，语法填空，改编)Diets have changed in China—and so too ________ its top crop.
答案：has 该句是一个倒装句。当前面的句子是肯定句时，用“so＋助动词/系动词/情态动词＋主语”表示“某人也……”。该句中助动词的选用根据前面句子的谓语动词来判断。
2．(2018·全国卷Ⅱ，70)China's approach to protecting its environment while ________ (feed) its citizens “offers useful lessons for agriculture and food policymakers worldwide，” says the bank's Juergen Voegele.
答案：feeding 此处是省略句。状语从句主语为it，谓语动词含有be动词时，可以省略it和be。由“连词＋doing”构成，表示主动的动作。相当于while it is feeding its citizens ...。
3．(2018·天津高考，5，改编)—I'm moving in a few days and I wonder if you could help.
—You bet. Just let me know when, ________ I'll be there.
答案：and 该句式是“祈使句＋and＋简单句”，祈使句相当于条件，简单句相当于主句。
