everyone is here let’s begin our meeting.A. SoB. As a resultC. UntilD. Since

问题补充：

everyone is here, let’s begin our meeting.

A. So

B. As a result

C. Until

D. Since

答案：

A. So

B. As a result

C. Until

(答案→)D. Since

解析：句意：由于大家都在这儿了，让我们开始会议吧。A因此 B结果是 C直到 D自从，由于；题中句子前面是原因后面是结果。故选D.