对乙状结肠的描述，正确的是（）。
A.始于左髂前上棘
B.至第3骶椎水平续于直肠
C.为腹膜间位器官
D.无系膜
E.由肠系膜上动脉供应
参考答案：B
正常血液pH维持在（）
A.7.00～7.05
B.7.15～7.25
C.7.35～7.45
D.7.55～7.65
E.7.75～7.85
Questions 11 to 15 are based on the following interview.
A. It turned out to be a complete failure for many residents. B. It was a big commercial success for project developers. C. It evolved in ways exactly as predicted by planners. D. It provided a fairly typical American housing landscape.
