关于try…catch语句说法正确的有()。
A.try代码块中编写可能发生异常的Java语句
B.catch代码块中编写针对异常进行处理的代码
C.catch代码块需要一个参数指明它所能够接收的异常类型
D.try…catch不是必须一起出现的,也可以只有try
A.try代码块中编写可能发生异常的Java语句
B.catch代码块中编写针对异常进行处理的代码
C.catch代码块需要一个参数指明它所能够接收的异常类型
D.try…catch不是必须一起出现的,也可以只有try
A.try语句后面必须要跟有catch语句
B.try语句后面可以跟有多个catch语句
C.catch语句可以不带参数
D.不论在try代码中是否发生了异常事件,finally语句块中的语句都会执行
A.从本地缓存中异步移除指定key
B.从本地缓存中同步移除指定key
C.异步清空本地数据缓存
D.同步清空本地数据缓存
"Mummy ! Mummy ! I saw some really big tadpoles (蝌蚪) in the pond (池塘). You've promised to catch some for us. "Phillip says, following me towards the kitchen. "Some of them have already got legs!" "Yes! We can catch them and watch them turn into frogs!" Geoffrey says suddenly. "Can we go? Right now?"The telephone has been ringing. I try to get the receiver, but it is too late. It has been cut off.
"Give me a minute to catch my breath. 'I beg. "Put the groceries away. Get some jars out. I'll go change."
We go to the wide pond which lies smooth and still, its surface dotted with pink (粉红色 ) and white lilies (睡莲). Phillip and Geoffrey, laughing and shouting, run to the water's edge. I feel the peace of the place broken by the children. I hope there are no tadpoles so we can leave quickly. There's dinner to cook.
It is quite some time before we have taken the first tadpole to the bank. "The children are wild with joy. Back in the pond we go, and we try hard to catch five more fat ones. We all agree that's enough. The sun has gone down. A frog goes to the opposite shore. It's well past dinner time, bath time and bedtime when we really leave. But none of us thinks of those things. Phillip and Geoffrey are in high spirits, and I am the same because I have done what I should.
Phillip and Geoffrey's voices must be ______.
A.sharp, nervous, tiresome
B.anxious, angry, inspiring
C.soft, sweet, pleasing
D.eager, excited, demanding
A.在while和for循环中,break语句的作用是终止当前循环,重新进入循环。
B.布尔运算符有一个很有趣的短路逻辑特性,即表达式x and y当x为假时,会直接返回False,不会去计算y的值。
C.if语句执行有一个特点,它是从上往下判断,如果在某个判断上是True,则执行该判断对应的语句,忽略剩下的elif和else。
D.在while和for循环中,continue语句的作用是停止当前循环,继续循环体下面的语句。
A.条件句中的选择值或标识符所代表的值必须在表达式的取值范围内
B. CASE语句中必须要有WHEN THERS=>NUL:语句
C.CASE语句中的选择值只能出现-次,且不允许有相同的选择值的条件语句出现
D. CASE语句执行必须选中,且只能选中所列条件语句中的一条
A.函数的三要素是函数名、参数和返回值,其中参数和返回值不是必须的
B.如果没有return语句,则Python函数默认返回值为None
C.函数可以嵌套
D.函数不可以嵌套
A.删除“学生成绩”表中数学成绩为空的所有记录
B.语法错误,改为数学=NULL
C.删除数学成绩非空的记录
D.只删除一条记录
完成下列各题 The people who lives in the far North are called Eskimos(爱斯基摩人).In the world of ice and snow it is 21 to grow plants for food.The Eskimos must hunt and fish during the whole year to 22 themselves and their families with food.In winter,they hunt the seal(海豹) 23 the polar(极地的)bear.When they hunt the seal,they 24 a hole in the ice and try to 25 the seal when it comes up to breathe. In summer,the Eskimos hunt 26 animals。and they also hunt birds and catch fish. 27 that is useful is saved.The Eskimos use the meat from animals for food.They melt(融化)the fat from their bodies and use the 28 as fuel(燃料).They make tools out of animals bones.The skin and furs of animals are used for making clothing. If an Eskimo is 29 lucky,he may kill a whale(鲸鱼), 30 a dead whale may wash up on the shore near his house.The whale is an especially useful animal,because it gives a great 31 of oil. There is 32 wood at all where the Eskimos live.Eskimos 33 all their wood from the sea.Sometimes floating wood from places.farther south washes up on the shore. Most Eskimo houses are 34 of stones.Instead of a door,there is a long,low tunnel (地道) 35 into the house.People have to crawl(爬)through the tunnel in order to enter the house.
A.important
B.impossible
C.impolite
D.interesting