已知：实数a，b在数轴上的位置如图所示，化简：$\sqrt{{\left(a+1\right)}^2}+2\sqrt{{\left(b-1\right)}^2}$﹣|a﹣b|．

已知：实数a，b在数轴上的位置如图所示，化简：$\sqrt{{\left(a+1\right)}^2}+2\sqrt{{\left(b-1\right)}^2}$﹣|a﹣b|．

On his way back home, Frank lost his wallet because of his {#blank#}1{#/blank#}（粗心）.

要使质量分数为10%的氯化钠溶液100g 变成质量分数为20%的氯化钠溶液，可采取的方法是（　　）

下列式子中，属于最简二次根式的是（　　）

阅读下面的短文，从每小题所给的A、B、C、D四个选项中，选出最佳选项。

Time zone:

Eastern Standard Time(EST): GMT+ 10 hours.

There is no daylight saving time in Queensland.

Legal drinking age:

18 years and older. Always keep your ID with you to prove your age.

Alcohol (酒) shops & hotels are the only places where alcohol can be bought.

Dangers:

Dial 000 from a fixed line or 112 from a mobile phone. Police, ambulance, fire.

Electricity:

240/250 volts AC 50Hz Universal outlets for 110 volts (shavers only) standard in hotels, apartments, motels.

Telephones:

Australian international code is 61.

Road rules:

Left hand side driving. There is a 50kmh speed limit in most living areas and on open highways100-110kmh. Seat belts must be worn all the time. If you want to hire a car, take along your driver's license.

No smoking:

Indoors: Indoor areas are no smoking.

Poker Machines: Poker machine areas are no smoking.

Outdoors: Non-enclosed eating and drinking areas are no smoking.

Swimming Safety:

ALWAYS SWIM BETWEEN THE RED AND YELLOW FLAGS and pay attention to the life guards' advice. Gold Coast beaches are guarded by skilled life guards and volunteers at weekends.