生物合成蛋白质时，氨基酸的活化形式是______；氨酰-tRNA中的氨基酰以______键与tRNA相连。
参考答案：氨酰-tRNA；酯
I arrived late and missed the flight. I _____ the traffic to be so heavy. [ ]
A. hadn't expected
B. haven't expected
C. wouldn't expect
D. was expected
现代物流的定义是什么？
