Mike spends a lot of his spare time on computergames.— So does my son. The children have becomehopelessly ________the games.

There are species living in the depths of the oceans ________ we still know little.[ ]

The problem ________ this material can be used in our factory has been solved

What has your hobby brought you— I think it has brought me happiness, especially itkeeps me _____ .

s that noise Is the water stillrunning— Oh, my god! I ________to turn itoff after I brushed my teeth．