They have been _ outsider for two hours.
举一反三
- By the time you arrive， I ________ working for two hours． A: will be B: can C: will have been D: have been
- The committee (A. has been arguing B. have been arguing) over the problem among themselves for two hours. A: has been arguing B: have been arguing
- They ______ TV for two hours. A: had watched B: are watching C: watched D: have been watching
- The captain turns out to have been ( ) for two hours. A: vague B: uppermost C: ashore D: useless
- Two hours (be) ____________ a short period of time during the working hours.