7 The new car that/which/whose we bought last year was very expensive.

7. The new car that/which we bought last year was very expensive.

В данном предложении нужно использовать местоимения that или which, так как оно относится к неодушевленному предмету (the car). Местоимение можно опустить: The new car we bought last year was very expensive.

Ответ: The new car that/which we bought last year was very expensive.