下图中的符号表示2个氢原子的是 [ ]
A．
B．
C．
D．
答案：C
左心衰竭的体征是（）
A．心界扩大
B．室性奔马律
C．浮肿
D．劳力性呼吸困难
Physics _____ my favorite while politics _____ her favorite. [ ]
A. is, are
B. are, are
C. are, is
D. is, is
