_______ everyone is here, let’s begin our meeting.

_______ everyone is here, let’s begin our meeting.

A. So B. As a result C. Until D. Since

______ everyone is here, let's begin our meeting.

[    ]

　　A. For   B. When   C. Since   D. Because

Since everyone________here，let's begin our meeting．

1. A.
   are
2. B.
   were
3. C.
   has been
4. D.
   is