单项选择(每题1分)The stones each _____ as much as two tons.
She_______ an old friend of hers yesterday while she was shopping at the department store.
Mrs Mavis said the aliens took her away so that they could do research _______ her.
Mr Smith will not be able to attend his sons wedding ceremony, because he_______ an important speech.
---The police have been______ the area for quite a long time.---I’ve also noticed that. What have they been______?
Then, a few months after Carter had opened the tomb, Lord Carnarvon_______ ill with a fever and died in Egypt.