关于无黏结预应力钢筋混凝土梁的优点，下列( )说法是不正确的。

Sometimes I feel that being the mother of three small c...

单项选择题Sometimes I feel that being the mother of three small children is like operating a large circus(马戏团).（21）afternoon last week, my three sons playing peacefully in the back yard(院子),（22）the ball from one to another. I jumped at the chance to talk to one of my friends（23）the phone, but before I（24）to the phone, I could tell the boys had begun to quarrel with each other about something. I rushed out to（25）peace, but before I got there Charles had（26）a rock at Mark, and hit him in the eye. By the time I got to the back yard, they had begun to（27）about this. Even David, the oldest boy, who won′ t usually fight with anybody about（28）, was involved(卷入,). First, I（29）them stop fighting, and then I examined Mark′ s eye. I decided that it wasn′t going to develop into a black eye, but I felt that they should（30）at least a little for（31）they had done "I′ m going to（32）to your father about this when he comes home for tomglat, said. "He and I will think of how to punish you. "Things were（33）quiet after that about half an hour, and then Charles（34）a glass in the kitchen, and at almost the same（35）, Mark fell out of the apple tree.
第（26）题选

已知RLC串联谐振电路，已知L=2mH，发生谐振的角频率ω0=1000rad/s，则电容C=_____μF。 ...

单项选择题已知RLC串联谐振电路，已知L=2mH，发生谐振的角频率ω0=1000rad/s，则电容C=_____μF。
A、1/2
B、50
C、200
D、500

Not many years ago, a wealthy and rather strange old ma...

单项选择题Not many years ago, a wealthy and rather strange old man named Johnson lived alone in a village in the south of England. He had made a lot of money in trading with foreign countries. When he was seventy-five, he gave ~ 1200 to the village school to buy land and equipment for a children′ s playground.
As a result of his kindness, many people came to visit him. Among them was a newspaperman.
During their talk, Johnson remarked that he was seventy-five and expected to live to be a hundred. The newspaperman asked him how he managed to be healthy at seventy-five. Johnson had a sense of humour (幽默). He liked whisky (威士忌酒) and drank some each day. "I have an injection(注射) in my neck each evening," he told the newspaperman, thinking of his evening glass of whisky.
The newspaperman did not understand what Johnson meant. In his newspaper he reported that Johnson was seventy-five and had a daily injection in his neck. Within a week Johnson received thou- sands of letters from all over Britain, asking him for the secret of his daily injection.
The gift of money to the school suggests that Johnson .