迷走神经分布的器官有（）
A.心脏
B.十二指肠
C.肺
D.横结肠
E.降结肠
参考答案：A, B, C, D
Teachers should _____ their students to practice _____ English as much as possible. [ ]
A. ask; speak
B. let; speak
C. keep; speaking
D. encourage; speaking
要改良细质土的通气性，只有当砂的加入量比需要改良的黏质土还要（）时才能达到目的。
A、一半
B、相等
C、少
D、多
