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. 

The intricate operation on the patient required the expertise of a/an ______ surgeon. 

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