（）是多变量质量分析的一种方法。
A、矩阵图法
B、系统图法
C、矩阵数据分析法
D、关联图法
参考答案：C
-I went to see you yesterday evening. But you weren't in. Where were you then?
-I _________ a walk by the lake with my husband.[ ]
A. was having
B. am having
C. have had
D. have
反应心脏收缩功能障碍最敏感的指标是
A．SV
B．CO
C．EF
D．PCWP
E．E／A
