1.Is Jim at home by himself

1.Is Jim at home by himself
No.There's another boy_____with him
A.playing B.play C.plays D.to getting
为什么不选C?
2.The sheep ____to the tree was found dead .How poor it is.
A.tied B.tying C.was tied D.was tying
3.Helen____ her keys in the office so she had to wait until her husband _____
A.has left;comes B.left;had come C.had left；came D.had left;would come
4.Tom ____ out
Oh,has he?What time ___he ____out?
A.is;did;go B.went;is;going C.has gone;did;go D.is going;does;go
答案和为什么