能兴奋腺苷酸环化酶的物质是()
A.凝血酶
B.PGH↓<2>
C.PGI2
D.TXA2
参考答案:C
—Hi,Jim. I_______ you for a long time.
—I_______ in Beijing for two months. I’ve just comeback. [ ]
A. didn’t see; have been
B. haven’t seen; was
C. didn’t see; was
D. haven’t seen; have been
下图为企业迁移与盈利空间变化示意图,SRC表示空间收入曲线,SCC和SCC′表示不同时期的空间成本曲线。读图,回答问题。
该图反映的现象是()。
A.产业升级
B.产业结构调整
C.企业的全球化
D.产业转移