窄轨接头应平整，轨面及内×差不得大于（）mm。
A.1
B.2
C.3
D.4
参考答案：B
按照《立法法》的规定，同一机关制定的特别规定的效力层级（）一般规定。
A.高于
B.低于
C.同等于
D.不高于
Please send us as soon as possible samples of the following goods _____ listed in your current catalogue.
A. which
B. as
C. what
D. for which
