宁波市夏季主要的自然灾害是____；

“无论哥伦布本人的内心动机怎样神秘，他航海得到支持，全靠有人从实际上来估计证实一条科学假设后所可期待得到的收获。”材料中所说的“科学假设”是（    ）

修改：在错的词下画一横线，并在该词下面写出修改后的词。

注意：1 每处错误及其修改均仅限一词；

2只允许修改10处，多者(从第11处起)不计分。

Aproverb says, “Time is money.” But in my opinions, time is even much valuablethan money. Why? Because when money is spent, we can earn them back, so whentime is wasted, we can never get it back. There is no doubt when time is verylimiting, and even an hour is of great value. We should make full use of timedo useful things. It's a pity that a lot of people didn't appreciate the valueof time. They waste their time doing anything useful. We should form the goodhabit of racing against the time.