请在每题B句中每一空格内填写一个词，使A，B两句意思相同。
1. A: He is old enough to join the army.
B: He is _____ old _____ he can join the army.
2. A: He is too young to go to school.
B: He is _____ old _____ _____ go to school.
3. A: The problem is so difficult that I can't work it out.
B: The problem isn't _____ _____ _____ _____ to work out.
4. A: The bag is too heavy for her to carry.
B: The bag is _____ heavy _____ _____ can't carry _____.
5. A: This pair of shoes is so dirty that nobody will wear it.
B: This pair of shoes is too dirty _____ _____ to wear.
6. A: He isn't tall enough to join the team.
B: He is _____ _____ _____ join the team.
7. A: I am very glad to do it for you.
B: I am _____ _____ glad to do it for you.
8. A: She hasn't enough time to do the work.
B: She has _____ _____ time to do the work.
