0.2 0.3 0.2 0.3 0.4 0. 1
Obviously, the part with an absolute value of 0. 1 is closest to the specified size, so the sixth part is the best.
Next question:
Because a+b=0, cd= 1, l m l=2.
Therefore [(a+b)/(a+b+c)]+m-cd.
=[0/(0+c)]+m- 1
=m- 1
= 1 or -3
18, obviously b>0> and l b l > l a l
So l a l -l b l=-a-b
19、a & lt-b & lt; 0 & ltb & lt-a & lt; letter of credit (L/C)
20、l -a l=2
Then a= 2 or -2, and the answer is C.