From Christianity and the barbarian kingdoms of the west emerged the medieval version of politics（）.in turn evolved the politics of our modern world.

单项选择题Not until the advent of histochemistry could the anatomist see through the microscope which cells carry specific enzymes or gauge how active these enzymes are in different cells under various conditions（）

A. discern
B. grasp
C. measure
D. estimate

单项选择题Your advice would be______valuable to him, who is at present at his wit’s end.