13. During class break, some of the students stayed indoors ________ others went out running in the field.
(A) instead
(B) as if
(C) so
(D) while

instead
adverb
in place of someone or something else
作為替代

There's no coffee - would you like a cup of tea instead?
沒有咖啡——來杯茶好嗎？

-

while
conjunction    while conjunction (DURING)
during the time that, or at the same time as
在…的時候；與…同時

I read it while you were drying your hair.
在你吹亁頭髮的時候，我讀了它。
While I was in Italy I went to see Alessandro.
在義大利的時候，我去看望了亞歷山德羅。

-

while conjunction (ALTHOUGH)
despite the fact that; although
雖然；儘管

While I accept that he's not perfect in many respects, I do actually like the man.
雖然我承認他在很多方面不是那麼完美，但我實際上還是非常喜歡這個男人。

While I fully understand your point of view, I also have some sympathy with Michael's.
儘管我能完全理解你的觀點，但我在一定程度上也贊同麥克的觀點。

-

while conjunction (BUT)

compared with the fact that; but
然而；但是

He gets £50,000 a year while I get a meagre £20,000!
他每年賺五萬英鎊，而我只有可憐的兩萬！

Tom is very extrovert and confident while Katy's shy and quiet.
湯姆性格外向，非常自信，而凱蒂卻羞澀文靜。

I do all the housework while he just does the dishes now and again.
樣樣家務我都要做，而他卻只是偶爾洗洗碗而已。