HELLO, SUSAN. IS ALAN HERE

13. Hello, Susan. Is Alan here? - No. I'm afraid, he ... out.

Mercury always keeps one side towards the sun. On this side it is always day, on the other side

always night. We only see the lighted side.

A. goes B. went C. going D. has gone

Mercury appears to us like a yellowish orange star. The nearest planet to the sun, it is always seen