M: The taxi driver must have been speeding.
W: Well, not really. He crashed into the tree because he was trying not to hit a box that had fallen off the truck ahead of him.
Question: What do we learn about the taxi driver().

A. He turned suddenly and ran into a tree.

B. He was hit by a fallen box from a truck.

C. He drove too fast and crashed into a truck.

D. He was trying to overtake the truck ahead of him.

关于胆汁溶菌试验，正确的是（）

A.是一种苷类代谢试验

B.是一种氨基酸代谢试验

C.是一种酶类试验

D.是一种抑菌试验

E.是一种增菌试验