Thorn of $Bougainvillea$ and tendril of $Cucurbita$ are examples of

There are two holes,one each along the opposite sides of a wide rectangular tank. The cross-section of each hole is $0.01 ~m^2$ and the vertical distance between the holes is $1 ~m$. The tank is filled with water. The net force on the tank in newtons when the water flows out of the holes is (Density of water $= 1000 ~kg/m^3$,$g = 10 ~m/s^2$):

Which one of the following molecular hydrides acts as a Lewis acid?

If $a > 0$ and $b^2 - 4ac = 0$,then the curve $y = ax^2 + bx + c$

Which one of the following reactions does not form a gaseous product?

Which part of the tobacco plant is infected by the nematode $Meloidogyne \ incognita$?