例句與造句

1. It underwent tethered trials between 1959 and 1962 but never flew untethered.
2. The reconstructed airship was inflated in June 1907 and after a series of tethered trials made its first free flight on 9 August, a short circuit returning to Sartrouville.
3. It's difficult to find tethered trial in a sentence. 用tethered trial造句挺難的