20 17 the first volume of eighth grade mathematics winter vacation homework answer page 65438 +06~ 18 Beijing normal university second grade mathematics winter vacation homework reference answer.
Answer: 1. 1.c Because there are countless symmetry axes 2. C because the dotted line of c is parallel to the dotted line of a, 2. Slightly 3. About four minutes. 1.=-x+2x-2-3x-5 =-2x-7 2。 = 5a+4c+7b+5c-3b-6a。