20. The horse is blind _____ the left eye.

21. He is very strict with others, but he is always blind _____ his own shortcomings.

22. We will never forget this historical lesson written _____ blood.

23. It is said that a bridge is being built _____ the river.

24. --- How did you go to work yesterday?

--- I went to work _____ my friend’s private car.

26. I called _____ you last night, but you were out.

27. You should write the first letter of the sentence _____ capital one.

28. He is too careful _____ his money; he never buys a drink for us.

29. Can you say _____ certain when he will come here?

30. More than 20 years ago he was badly wounded in the anti-Vietnam war. Since then he can only walk _____ an arm-chair .