题干
Who ______ the fight against the H1N1 flu ______ it not been for the Chinese scientists’ great efforts?
A：could have won; had
B：would win; had
C：would have won; ha
D：could win; ha
答案(点此获取答案解析）
A
是（ ）
轴正方向传播，处在
和
的两质点
、
的振动图像如图所示。由此可知（ ）
