Questions

While moving from left to right in periodic table basic character of oxide of elements will decrease.

  ∴→Increasing basic strengthAl2O3<MgO<Na2O 

and while descending in the group basic character of corresponding oxides increases. 

 ∴→Increasing basic strengthNa2O<K2O

∴ Correct Order is Al2O3 < MgO <Na2O <K2O

Although it is less accurate than adding up individual costs from the WBS, it is less time consuming. The trade-off is accuracy. Answer A is incorrect because to do a more accurate cost estimate, you need to delve into details. Answer C is tempting also, and possible, except we don't really know if the project in question can use perametric modeling . Answer D is incorrect because it takes the most time, but it is most accurate.

Controlled railroad crossing includes warning signs, red lights and railway gates, whereas absence of all of these warning signs like red lights and gates includes uncontrolled railroad crossings. 

China flicked the switch on the world’s largest floating solar energy plant.  The massive waterborne plant is expected to generate 40 megawatts at one time and could supply electricity for over 15,000 homes. The pioneering project, located in eastern China, is thought to cement China’s status as a top producer of solar energy in the world.  The plant has been built in Huainan city, Anhui Province, by Sungrow Power Supply, a Chinese company specialised in renewable energy.

The correct statement from the given options is

The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.