The origins of human speech remain a mystery,__________ we have a fairly accurate idea of when writing began.

2023-08-04

A. once
B. if
C. though
D. since

参考答案:C

考查连词辨析。句意为“我们对于写作的起始有了相当准确的观点,演讲的。起源仍然是个谜团”。根据句意.前后表转折.故选C。

相关推荐