Preopsitions 2 --> 20pts

25. We must help those in danger at all costs.26. He sat down at the table and started working.27. They live on the second floor of this mansion.28. She made a mistake by adding salt instead of sugar.29. He was concerned about the poor performance in the exam and finally he came to the decision that he should study harder.30. Did you stay with your friends? No, I stayed in the hotel.31. The house is built by the sea.32. Freedom is something people must fight for.33. Do you take tea with milk and sugar?34. Who is the man with the sunglasses on?35. I love any music by the Beatles.36. My friend wants a house with a garden.37. Look! He’s standing by the window.38. I like movies with happy endings.39. The headline is at the top of the page.40. The boys are playing football in the street.41. He reminds me of my brother.42. Are you still working on the project?43. After the discussion, they have finally came to a conclusion.44. Health depends on good food, fresh air and enough sleep.45. The horse jumped over the fence. 46. We went to Boston on vacation.47. We assure our clients of an enjoyable holiday.48. Fighting against crime is the duty of every citizen.49. She completed the work at the expense of her health.50. Dr Smith specializes in children’s diseases.

25.   We must helpthose in danger AT all costs.26.   He sat down  AT the table and started working.27.   They live ON thesecond floor of this mansion.28.   She made amistake BY adding salt instead of sugar.29.   He was concerned ABOUT the poor performance in the examand finally he came TO  the decision thathe should study harder.30.   Did you stay WITH your friends? No, I stayed IN the hotel.31.   The house isbuilt BY the sea.32.   Freedom issomething people must fight FOR.33.   Do you take tea  WITH milk and sugar?34.   Who is the man WITHthe sunglasses on?35.   I love any musicOF the Beatles.36.   My friend wantsa house WITH a garden.37.   Look!  He’sstanding BY  the window.38.   I like movies WITHhappy endings.39.   The headline is AT the top of the page.40.   The boys areplaying football IN (UK) /ON (US) the street.41.   He reminds me OF my brother.42.   Are you stillworking ON the project?43.   After thediscussion, they have finally came TO a conclusion.44.   Health depends ONgood food, fresh air and enough sleep.45.   The horse jumped OVER the fence.46.   We went to Boston ON vacation.47.   We assure ourclients OF an enjoyable holiday.48.   Fighting  AGAINSTcrime is the duty of every citizen.49.   She completedthe work AT the expense of her health.50.   Dr Smith specializes IN children’s diseases.
Comment:
AT ALL COST(S) is a common phrase.
 
ON VACATION:
We usually say "on vacation", except "Where did you go for your vacation?"





2010-08-14 22:17:28 補充：
There should be a space between two words,
ONgood should be "On good"; WITHhappy should be "WITH happy"

My editor is not working properly.

25. by
26. at
27. on
28. by
29. about , to
30. with , in
31. alongside/ by
32. for
33. with
34. with
35. of
36.with
37.by
38. with
39. at
40. in
41. of
42. on
43. to
44. on
45. over
46. during
47. of
48. against
49. at
50. in