When / If you want to become a mentor, you need to be an expert in the field you choose.

Read the LANGUAGE FOCUS and choose the most appropriate conjunction in sentences 1-5 below. (Đọc LANGUAGE FOCUS và chọn cách kết hợp thích hợp nhất trong các câu 1-5 dưới đây.)

1. When / If you want to become a mentor, you need to be an expert in the field you choose.