首先，这几道题涉及到英语构词法的前缀。我们来一起看题：
1. If they are co-producers, they produce something ____.
2. What he said is illogical. Here illogical means ___ logical.
3. An irregular verb is a verb which is ___ regular.
4. He lived a hard life in pre-liberation days, that is, the days ___ liberation.
5.They go to work by subway which means the railway ___ the ground.
6. If the temperature is sub-zero, the temperature is ___ zero.
7. A supermarket is a ___ self-service store selling food, household goods, etc.
8. An anti-tank weapon is a weapon ___ tanks.
其次，这几道题的答案如下：
1. together 2. not 3. not 4. before 5. under 6. below 7. large 8. against
再者，我们需要学习一下这八道题中的前缀用法：
co-: together, with 例如：co-operation
il-: not 例如： illegal
ir-: not 例如：irrelative
pre-: before 例如：pre-exist
sub-: under, behind 例如：subtitle
super-: above, greater than 例如：super-power
anti-: against 例如：anti-war
希望以上的解答对您的英语学习有所帮助，祝学习快乐！
together 2.not 3.not 4.before 5.under 6.below 7.large 8.against
1.together一起合作
2.not 3.not
4.before 5.on 6.below
7.super 8.fighting反坦克武器