We/ survive/ unless/ start/ work/ cleaner/ safer/...

Câu hỏi: We/ survive/ unless/ start/ work/ cleaner/ safer/ sources/ energy.

A. We won't survive unless we start working cleaner, safer sources of energy.

B. We won't survive unless we start work on cleaner, safer sources of energy.

C. We will survive unless we start to work cleaner, safer sources of energy.

D. We won't survive unless we start working on cleaner, safer sources of energy.