The first thing ________ I did was to see if there were any products ________ might help me, but there only seemed to be powders ________ to kill snakes.
A.that; /; designed
B.which; that; designed
C./; that; designed
D./; which; design
网友回答
C解析考查定语从句和分词用法。第一空省略that/which, that/which指代先行词the first thing作为did的宾语；第二空that指代any products在句中做主语，不能省略。Design与powders构成被动关系，所以使用过去分词。