---How do you find my composition, Mr John? ---Good, ___too many spelling mistakes. You can’t imagine what great difficulty I had ___them.

Once new difficulties  ________in your work, it’s always important to use your brains.

In my brother's absence, I would like to thank all concerned on his ________.

(2013·安徽蚌埠一次质检)Finding information in today's world is easy.The ________ is how you can tell if the information you get is useful or not.

Anyone who refuses to ____ with others is not likely to be given a job that involves teamwork.