划分发展中国家和发达国家的依据是[ ]
A．人口的多少
B．人种的差异
C．军事力量的强弱
D．经济发展水平
答案：D
—Can I my hair colored, Mom?
—No. As a student, you ________ do that.
A．let; are allowed to
B．got; should be allowed to
C．get;may not
D．get; shouldn’t be allowed to
液压系统常见的故障表现形式有噪声、（）和油温过高等。
