Which is the best method to conserve the wild relatives of plants?

If $A, B, C, D$ are angles of a cyclic quadrilateral,then $\cos A + \cos B + \cos C + \cos D$ is equal to

If the tangent to the curve $y = \frac{x}{x^2 - 3}$,$x \in R$,$(x \neq \pm \sqrt{3})$ at a point $(\alpha, \beta) \neq (0, 0)$ on it is parallel to the line $2x + 6y - 11 = 0$,then:

Which herbicide is derived from urea and is used for weed control in tea, cotton, and tobacco crops?

The equation of the plane containing the line $\frac{x + 1}{-3} = \frac{y - 3}{2} = \frac{z + 2}{1}$ and the point $(0, 7, -7)$ is

The normal at the point $(1,1)$ on the curve $2y + x^{2} = 3$ is