Directions : Each of the following sentences in this section has a blank space, followed by four options. Select the most appropriate option to fill in the blank and mark your response on the Answer Sheet accordingly. 

There are ______ thirty students inside the classroom at any time. 

Directions : Each of the following sentences in this section has a blank space, followed by four options. Select the most appropriate option to fill in the blank and mark your response on the Answer Sheet accordingly. 

There are many _______ vehicles on the highway due to a sudden landslide. 

The focal length of a concave lens is 0.5 m. The power of the lens is 

The rule to determine the direction of a force experienced by a straight current carrying conductor placed in a magnetic field which is perpendicular to it is