— That mountain in Guilin ________ an elephant.
— So it does. It's amazing!
A:looks up
B:looks like
C:looks for
D:looks after
在图所示的质粒PZHZ11(总长为3.6kb,1kb=1000对碱基因)中,lacZ基因编码β﹣半乳糖苷酶,后者催化生成的化合物能将变色的大肠杆菌染成蓝色.