Word came ________ our country has sent up another man-made satellite. I was always wondering ________ the scientist managed to make such a great achievement.
A:which; why
B:that; why
C:that; how
D:when; how
由方程x+t=5,y﹣2t=4组成的方程组可得x,y的关系式是( )
①除了你,谁是我在无遮无拦天空下的yīn bì____。
②那像是滑轮的响声,很不引人注意,又像是干皱的薄膜隐隐约约的 xī sū____作响。
③我看见奔流似的马群,深夜 háo míng____的蒙古狗。
④他从唐诗下手,目不窥园,足不下楼,wù wù qióng nián ____,沥尽心血。