表示随机选择分配和控制的符号是()
A.X
B.B
C.O
D.R
参考答案:D
There is a new problem________in the popularity of private cars that road conditions need improving..[ ]
A.involved
B.to involve
C.involving
D.being involved
个人的短期目标最好要随时调整,长期目标最好不要调整。