Questions

a) joins the Gulf of Mexico and Atlantic Ocean, and touches USA and Bahama Island.

b) joins the sea of Marmara and Aegean Sea, touching Asian Turckey and European  Turkey

d) joins Black sea and sea of Marmara touching Asian Turkey and European Turkey

Cache momory is a small high-speed memory. it is used for temporary storage of data & information between the main memory and the CPU(center processing unit). The cache memory is only in RAM.

Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. AS the microprocessor processes data, it looks in the cache memory and if it finds the data there.

Photosynthesis is the process that converts solar energy into chemical energy. During the stage of light-dependent reactions involving photosystems I and II in photosynthesis, O2 produced.

Fragmentation occurs in a dynamic memory allocation system when many of the free blocks are too small to satisfy any request.

The given sentence is in simple present tense and states a general fact, hence the latter half of the sentence with the blank will also be in the simple present tense. Since the subject in the latter part of the sentence is singular .i.e. 'the number', the verb will be followed accordingly. Hence, option 4 is the correct answer.