To improve the quality of our products ,we  asks  for suggestions      had  used  the products.

A.whoever     B. who       C. whichever    D.which

To improve the quality of our products, we asks for suggestions      had used the products.

A．whoever             B．who           C．whichever            D．which

To improve the quality of our products ,we  asks  for suggestions         had  used  the products

1. A.
   whoever
2. B.
   who
3. C.
   whichever
4. D.
   which