Question

8. You must keep on working in the evening,         you are sure you can finish the task on time.

Answer 1

8. unless 此處unless引導(dǎo)一個(gè)狀語從句，意思同if—not。句意：你必須在晚上繼續(xù)工作，除非你確保你能按時(shí)完成任務(wù)。