________ tourists like to climb the Great Wall, and ________ them is increasing now.
A:A great number of; a number of
B:The number of; the number of
C:The number of; a great number of
D:A great number of; the number of
甲口袋中装有两个相同的小球,它们的标号分别为2和5,乙口袋中装有两个相同的小球,它们的标号分别为4和9,丙口袋中装有三个相同的小球,它们的标号分别为1,6,7.从这3个口袋中各随机取出一个小球.
噬菌体在细菌细胞内合成自己的蛋白质需要( )