11. come up with 提出

10. now that 既然

9. make a contribution to... 为……作贡献

8. keep track of 保持联系

7. trial and error 反复试验

6. be aware of 意识到

5. break away from 摆脱

4. get stuck 遇到困难

3. allow for 顾及

2. get used to 习惯于