Dưới đây là các từ thích hợp để điền vào chỗ trống:

1. (3) **filtered** (lọc)
2. (4) **harden** (cứng lại)
3. (5) **processed** (xử lý)
4. (6) **chemicals** (hoá chất)
5. (7) **then** (sau đó)
6. (8) **products** (sản phẩm)

Vì vậy, đoạn văn đầy đủ sẽ là:

"After the latex has been **filtered** and the dirt removed, it is poured into large tanks and left to **harden**. When the latex is hardened, it is dried and sent to factories. At the factories, the rubber is **processed** into thin sheets and special **chemicals** are added to it. The sheets of rubber are **then** sent to other factories which manufacture rubber **products**."