Although there is no life on Mars now , some scientists think that there some form of life a long time ago .
| A．must be | B．may have been | C．can have been | D．could be |
If I can help _______, I prefer living in Hangzhou because the weather here is better than _______ of Suzhou.
| A．one, it | B．it, that | C．that, one | D．it, it |
I have won a holiday for two weeks to Florida. I ________ my Mum.
| A．am taking | B．have taken | C．take | D．will have taken |
---Do you know our town at all?
---No, this is the first time I ________ here.
| A．was | B．am coming | C．came | D．have come |
We won’t give up _______ we should fail 10 times.
| A．since | B．as if | C．whether | D．even if |
With the guide leading the way we were able to travel ___ the forest not ___ air but __foot.
| A．through; by; on | B．across; by; on | C．past; on; by | D．into; on; by |