1. Listening Comprehension(每题1分,共20分) 1.c2.c3.b4.b5.c6.c7.b8.b9.c10.b11.12.a13.a14.a15.b16.d 17.d18.b19.d20.B

一、选择题 A型题 1.c2.c3.c4.b5.d6.b7.e8.d9.a10.d11.b12.b 13.b14.e15.16.C17.C18.C19.20.b21.d22.d23.c 24.b25.e26.e27.c28.c29.d30.c31.a32.a33.b34.d

Let A and B be sets. A function f from A to B is an assignment of exactly one element of B to each element of A. We write f(a) = b if b is the unique element of B assigned by the function f to the element a of A. If f is a function from A to B, we write f : A→B

4.5线性方程组解的结构 b 齐次方程组Ax=0 非齐次方程组Ax=b(b≠0) 结论:(1)[4b]→[d,Ax=b与Cx=d同解 (2)Ax=0有非零解兮rank4