Fill in:
NASA __ does many tests before flying a new spaceship, __ the Boeing Starliner didn't reach the space station. It went to the wrong orbit. Now the ship is __ in space.
a. yet
b. still
c. always
日本語訳
NASAは新しい宇宙船を飛ばす前にはいつも多くの試験をします。それなのに、ボーイングのスターライナーは宇宙ステーションに到達できず、別の軌道に入りました。いまも宇宙にあります。空欄に always／yet／still を入れてください。
解答・解説
The answers are: c, a, b; look:NASA _always_ does many tests before flying a new spaceship, _yet_ the Boeing Starliner didn't reach the space station. It went to the wrong orbit. Now the ship is _still_ in space.
Explanation
The first answer. Always refers to repeated, cyclic and unchanging conditions, habits, protocols or procedures. 'Still' would be grammatically okay here, but it is needed elsewhere in the passage, and in that place where it belongs, the other choices would also work grammatically but not be the best and/or not make sense.
The next answer, 'yet', provides a contrast with the information and adverb 'always' in the first answer; 'always' indicates something continuous or repeating without fail under certain conditions--and thereafter, 'yet' tells us a break in that consistency is coming. 'Yet' also acts like the conjunction 'but'.
Finally, the last answer, 'still' tells of a thing that has not ended. Again, all the options work in the space, but then in the other combinations would not make sense.
順に always（いつも）、yet（それなのに）、still（まだ）です。always は繰り返される習慣や手順、yet は「いつも試験する」ことと失敗という結果の対比、still はその状態が続いていることを示します。ほかの語も一部の空欄には文法上入れられますが、全体の意味に合う組み合わせを選ぶ問題です。宇宙船の状態は記事執筆時点の記述です。