A:测得该液体pH=7
B:测其KW为1×l0-14
C:向其中投入金属钠,钠于液面上迅速游动,并发出丝丝声
D:在1.0l×l05Pa压强下测得沸点为100℃
There used to ____ (be) a lot of manatees. But now there are few.