Put the verbs in brackets in the past simple tense or past perfect tense.
1. Neil Armstrong and Buzz Aldrin (collect)________ some moon dust samples before they (return) _________ to Earth.
2. By the time Yang Liwei (become)________ the first person sent into space by the Chinese space program in 2003, NASA already (send) ________ over 100 people.
3. After the spaceship Soyuz 37 (be) __________ in orbit around the earth, Pham Tuan and Viktor Gorbatko (conduct)_________ some experiments.
4. When we (arrive)________ in Kennedy Space Center, the space shuttle already (launch) ________ into space.
5. Dennis Tito already (complete)_______ 900 hours of training by the time he (fly) ________into space in 2001.
1. Neil Armstrong and Buzz Aldrin (collect)____.had collected____ some moon dust samples before they (return) ____returned._____ to Earth.
2. By the time Yang Liwei (become)____.became____ the first person sent into space by the Chinese space program in 2003, NASA had already (send) __ sent.__ over 100 people.
3. After the spaceship Soyuz 37 (be) ______.had been____ in orbit around the earth, Pham Tuan and Viktor Gorbatko (conduct)____.conducted._____ some experiments.
4. When we (arrive)__arrived______ in Kennedy Space Center, the space shuttle had already (launch) _____. launched.___ into space.
5.Dennis Tito had already (complete)___.completed.____ 900 hours of training by the time he (fly) _____.flew___into space in 2001.
1. Neil Armstrong and Buzz Aldrin had collected some moon dust samples before they returned to Earth.
2. By the time Yang Liwei became the first person sent into space by the Chinese space program in 2003, NASA already had already sent over 100 people.
3. After the spaceship Soyuz 37 had been in orbit around the earth, Pham Tuan and Viktor Gorbatko conducted some experiments.
4. When we arrived in Kennedy Space Center, the space shuttle already had already launched into space.
5. Dennis Tito already had already completed 900 hours of training by the time he flew into space in 2001.