3.(2019浙江宁波北仑二模,61) Sure, turtles may be slow but they keep 　　     (go).

答案　going　考查动名词作宾语。句意:当然,乌龟也许很慢,但是它们保持前进。keep后跟动名词作宾语,表示“持续做某事”,故填going。

4.(2019浙北名校联盟,63)Even with all the new technology since Armstrong's time, it would cost much for people　　    (return)to the Moon.

答案　 to return    考查非谓语动词。句意:即使有了阿姆斯特朗时代以来的所有新技术,人们重返月球的成本也会很高。此处,所填词作句子的主语,因此用动词不定式。