选择题：The origins of human speech remain a mystery,__________ we have a fairly accurat

题目内容：

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

A.once

B.if

C.though

D.since

参考答案：【答案仅供学习，请勿对照自行用药等】

答案解析：

__________in some areas in Anhui Province that people put on their shirts or dre

__________in some areas in Anhui Province that people put on their shirts or dresses soon after taki

分类：教师资格题型：选择题

What is the teacher doing in terms on error correction?" Make a sentence with "have"!S: He have a ca

分类：教师资格题型：选择题

The thing that__________is not whether you fail or not, but whether you try or not.

分类：教师资格题型：选择题

分类：教师资格题型：选择题

分类：教师资格题型：选择题