题目内容：
Umbrellas are common in our daily life. On rainy days, many people hold them to prevent the 21 .But it's not easy to hold an umbrella if there is 22 rain and 23 winD．And it's harder to make a phone call or ride a bike 24 an umbrella 25 the hanD．An American named Kaufman and his company 26 6 years inventing a hand-free umbrellA． 27 .They made it. They called it NubrellA． Just touch a button(按钮),and the Nubrella will open 28 .With the help of its "shoulder support(支持)", the umbrella 29 rest on the user's 30 . 31 the user needn't hold the umbrella any more.He can walk with hands 32 even in the strong winD． The hand-free umbrella is $59.94 each. People 33 around the word like it very much. Because of this smart 34 they can use their phones to talk and send short messages in the rain now. 35 in the rain under a Nubrella is really cool. isn't it?
根据上文，回答题
A．snow
B．water
C．sun
D．cloud
参考答案：
答案解析：