58.（）

Since computers were introduced, they____ to be useful tools for people weak in math.

• A、had proved

• B、have proved

• C、 will prove

• D、are proving

Directions:In each of the following groups of words, there are four underlined letters or ltter combinations marked A, B, C and D. Compare the underlined parts and identify the one that is different from the others in pronunciation. Mark your answer by blackening the corresponding letter on the Answer Sheet

• A、 sweat

• B、 please 

• C、beat

• D、meat