直肠脱的常见诱因是()。
A、肝炎、胰腺炎
B、胃扩张、胃穿孔
C、胃炎、胃溃疡
D、便秘、腹泻
E、腹膜炎、胸膜炎
参考答案:D
Mr Smith ______ to American 10 years ago and has been there ______.[ ]
A. has gone, since then
B. went, from then
C. has gone, since then
D. came, ever since
以网络机器手搜索为标志的搜索引擎类型是()。
A.分类目录型搜索引擎
B.元搜索引擎
C.技术型搜索引擎
D.人工搜索引擎