（）金属探测门的工作原理是设备发生的一连串的脉冲信号产生一个时变磁场，该磁场对探测区

阅读下面的短文，请根据文后的要求答题（注意问题后的词数要求）

Michelle and Barney Wanstall rode off into the Lake District sunshine yesterday with no trouble at all.

They were the first customers to try a new electric bicycle hire service aimed at tourists who want the fun of cycling without pain. “We wanted to go on a boat when we first got here,” explained Mr. Wanstall, a student. “But we saw these bikes and decided to hire them instead.”

Brian Eaton, owner of Easyriders, which has a dozen bicycles for hire by the side of the lake near Coniston village, smiled as Michelle looked anxiously at Coniston Old Man, the mountain that towers over the village.

“We do quite a lot of cycling at home,” said Michelle. “But with mountains everywhere, it’ll be easier if we _______________________. And it’s only £18 each for a day’s easy riding and the chance to enjoy some of the finest countryside in Britain!”

The motorized bicycles helped the couple as soon as they began to pedal; they would have needed to use twice as much energy with a normal bicycle. The bicycles are very safe; they cannot go faster than 15 mph and the special tyres cannot be punctured. “It’s easy riding,” said Mr. Eaton. “There are a lot of people fancy cycling, but are not as fit as they used to be!”

Riders are provided with helmets, maps, routes and suggestions for picnics and places to stay. Most electric bicycles are sold in Japan. However, Mr. Eaton thought they would be popular with tourists in the Lake District. “As far as I know, these are the only motorized bicycles for hire in the country,” he said. “If the idea is successful, I’ll set up other hire centres around Britain.”

1. This passage is mainly about ______________________________________. (within 10 words)

2. What are the two ways of going on a tour in the Lake District according to the passage? (within 8 words)

①___________________ ②___________________

3. Finish the following sentence according to the passage. (within 8 words together)

With an electric bicycle, they needed only _____________________________ with a normal bicycle.

4. What do the underlined words “the mountain” refer to? (within 5 words)

____________________________________________________

5. Fill in the blank in the fourth paragraph. (within 7 words)

_____________________________________________________

我国《证券法》规定，证券业和银行业、信托业、保险业（）。

A.混业经营、集中管理

B.混业经营、分业管理

C.分业经营、分业管理

D.分业经营、统一管理

甲乙两数之积为1，则甲乙两数都是倒数．______．

以上为缓冲剂的是

A．苯酚
B．亚硫酸氢钠
C．盐酸利多卡因
D．羧甲基纤维素钠
E．枸橼酸

标准麻花钻主切削刃外缘处的刀尖角较小，前角（），刀齿薄弱，速度高，磨损极为严重。

A．很大

B．为零

C．很小

D．与别处相同