1.   Although a new and growing field in medicine, placental blood transfusions have proved effective in combating leukemia and other cancers.

2.   As existing dominant males age so doubtless can the collaborative attacks of younger animals prove increasingly effective.

3.   It has proved extremely effective over the past few years.

4.   Malarone has already proved highly effective in other trials.

5.   Malarone is a new drug that has already proved highly effective.

6.   Standing it on a block of foam rubber, filter matting, or a piece of polystyrene tile can also prove effective.

7.   The relationship with the National Council for Vocational Qualifications develops slowly, but our moves to ensure the continuing provision of tuition for banking candidates have proved effective.

8.   Shopwatch only started at the beginning of the year but is already proving effective deterring some casual shoplifters.