手机可以根据（）中的PRL文件搜索指定载频的EV-DO网络
A.终端
B.UIM卡
C.AN-AAA
D.HLR
参考答案：A, B
Why not _____ your teacher for help when you can't finish _____ it by yourself? [ ]
A. ask; write
B. to ask; writing
C. ask; writing
D. asking; write
下列各项中，能正确表示食物链的是[ ]
A．草←虫←鸟
B．草→虫→鸟
C．阳光→草→虫→鸟
D．阳光←草←虫←鸟
