This washing machine is environmentally friendly because it uses （ ） water and electricity than （ ） models.
（A）less; older
（B）less; elder
（C）fewer; older
（D）fewer; elder
To plant the tree, we must dig （ ）.
（A）a three - feet - deep hole
（B）three - foot - deep a hole
（C）a hole three feet deep
（D）a three - foot - deep hole
He didn’t （ ） and so he failed the examination.
（A）work enough hard
（B）work hard enough
（C）hard work enough
（D）hard enough work
