Or do they copy one another, perhaps (9) ________ envy or perhaps because they have shared information about the products?

Đáp án C.

Tạm dịch: Or do they copy one another, perhaps (6)______ envy or perhaps because they have shared information about the products?: Hay bởi họ bắt chước lẫn nhau, có lẽ ______ ghen tị hoặc có lẽ do họ cùng chia sẻ thông tin về sản phẩm?

Cấu trúc: out of envy = because of envy: bởi sự ghen tị, do ghen tị