城市道路的垫层厚度可按当地经验确定，一般宜大于或等于()mm。
A.50
B.100
C.120
D.150
参考答案：D
超车时应从前车的左侧超越，是因为左侧超车便于观察，有利于安全。
______recent report stated that the number of Spanish speakers in the U. S . would be higher than the number of English speaker by_____ year 2090.
A, the B. A, / C. The ,/ D. The, a
