There are many difficulties in front of me. _____, I still keep on trying and work for a better future. [ ]

A. Moreover

B. Nevertheless

C. Otherwise

D. Instead

小儿皮质下中枢的兴奋性较高，但皮质发育未完善，对皮质下中枢不能控制，所以它的兴奋和抑制过程容易扩散。这就可以解释为什么婴幼儿遇到强烈刺激时，容易发生（）

A.呕吐

B.发热

C.睡眠

D.惊厥

E.腹泻