The plane shook violently(剧烈的) ____ it touched the ground and then moved rapidly __90__ the runway and after a long run it stopped safely.A) as B) unless C) while D) so为什么不选C

The plane shook violently(剧烈的) ____ it touched the ground and then moved rapidly __90__ the runway and after a long run it stopped safely.A) as B) unless C) while D) so为什么不选C
The plane shook violently(剧烈的) ____ it touched the ground and then moved rapidly __90__ the runway and after a long run it stopped safely.
A) as B) unless C) while D) so
为什么不选C

The plane shook violently(剧烈的) ____ it touched the ground and then moved rapidly __90__ the runway and after a long run it stopped safely.A) as B) unless C) while D) so为什么不选C
while 后面的动词必须是延续性动词, 而 touch 不是.

选C的后面就应该是进行时态了，所以，，

while 后面不是一般过去时