Which of the following aquatic ferns is used as an excellent biofertilizer?

Clamp connection is found in

$A$ projectile is fired from the surface of the earth with a velocity of $5\, ms^{-1}$ at an angle $\theta$ with the horizontal. Another projectile fired from another planet with a velocity of $3\, ms^{-1}$ at the same angle follows a trajectory which is identical to the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is (in $ms^{-2}$) (given $g = 9.8\, ms^{-2}$):

The equation of a pair of lines is given by a second-degree homogeneous equation. If one of them is perpendicular to the line $x+2y+7=0$ and the other line is parallel to the line $3x+4y+5=0$,then the equation of that pair of lines is:

$A$ cup of coffee cools from $90^{\circ} C$ to $80^{\circ} C$ in $t$ minutes,when the room temperature is $20^{\circ} C$. The time taken by a similar cup of coffee to cool from $80^{\circ} C$ to $60^{\circ} C$ at a room temperature same at $20^{\circ} C$ is :

The parabola with directrix $x+2y-1=0$ and focus $(1,0)$ is