南京长江大桥全长6.772千米．6.772读作______．
南京长江大桥全长6.772千米，6.772读作：六点七七二；
故答案为：六点七七二．
-When did you become a volunteer for the elderly?
-Two years ago. I ______ this group since then.[ ]
A. joined
B. took part in
C. have joined
D. have been in
该病成人的完全治愈率约为
A．10%B．20%～40%C．50%～75%D．85%～90%E．95%
r the elderly?