Which of the following is mostly likely the reason why sandwich courses are increasingly popular?  

Read the following passage and mark the letter A, B, C or D on your answer sheet to choose the word or phrase that best fits each other numbered blanks. 

     Since mobile phones’ explosion in popularity, many schools have resisted, or even banned, their use in the classroom. Yet an increasing (34) _______ of educators are now turning to cell phones in order to bolster student engagement and learning (35) _______ mobile-phone use should be limited to situations where the technology genuinely enhances instruction, the advanced functionality of today's cell phones makes them ideal for 2 1st century lessons. For example, many schools use the devices to poll students in class via text message.  Some schools encourage students to use their phones Cameras to snap pictures for use as inspiration in an classes. Others allow students to capture photographs of a post-lecture whiteboard. In seconds, kids car grab a detailed image of a teacher's notes on the board and email it themselves, resulting (36)  _______ incredible study tool.  

     On field (37) _______, students can participate in scavenger hunts by snapping pictures of items on a teacher-supplied list. Mobile phones can also help (38) _______ class discussion. Teachers might ask students to run a Google Search for information on a particular topic. An alternative to presenting the information via lecture or having students read it from a textbook, discussion-integrated Web searches are potentially more engaging, increasing the adds that students will retain the information.