题目

--Will you __________ our pet dog while we're on vacation? --Well, that ought to be no problem. A. keep an eye of     B. keep an eye on C. have an eye for     D. have an eye on   答案：B一个人连续不断地在纸上写出1234567891011121314直到999999，估计大约需要多少时间？(按每1秒写10个数字，1㎝能写3个数字计算)