完成句子。

1. 我经常骑自行车去上学,但有时候步行.

I often go to school by bike, but ______ I walk.

2. 格林夫妇明年的某个时候将来中国,他们将会在这儿呆一段时间.

The Greens will come to China ______ next year and they will stay here for ______ ______ .

3. 他有很多关于学英语的信息.

He has got ______ ______ about learning English.

欲把当前目录下的file1.txt复制为file2.txt，正确的命令是（）。

A.copyfile1.txtfile2.txt

B.cpfile1.txt|file2.txt

C.catfile2.txtfile1.txt

D.catfile1.txt>file2.txt