3333

世界上第一部《医学伦理学》于（ ）年出版。 A: 1801 B: 1802 C: 1803 D: 1804 E: 1805

It is generally believed that the year of chemistry was established in: A: 1869 AD B: 1661 AD C: 1829 AD D: 1680 AD E: 1945AD

​import json a = {'a':'1111','b':'2222','c':'3333','d':'4444'} jsObj = json.dumps(a) print(jsObj) print(type(a)) print(type(jsObj))运行结果是：‌​‌ A: {"a": "1111", "b": "2222", "c": "3333", "d": "4444"} <class 'dict'> <class 'dict'> B: {"a": "1111", "b": "2222", "c": "3333", "d": "4444"} <class 'str'> <class 'str'> C: {"a": "1111", "b": "2222", "c": "3333", "d": "4444"} <class 'dict'> <class 'str'> D: {"a": "1111", "b": "2222", "c": "3333", "d": "4444"}<class 'str'><class 'dict'>

DR摄影过程中() A: 经过AD转换 B: 不确定是否经过AD转换 C: 不经过AD转换 D: 部分经过AD转换出需 E: 最后经过AD转换

In 1803 the United States purchased Louisiana from _____.

已知关系模式R（A, B, C, D, E, G, H），函数依赖集F为{AD→EH, DC→BH,H→G, D→H, A→D}，则F的最小函数依赖集是（ ）。? {AD→E, CD→B, H→G, D→H, A→D}|{AD→E, AD→H, CD→H, CD→B, H→G,D→H, A→D}|{A→E, CD→B, H→G, D→H, A→D}|{A→E, AD→H, CD→B, H→G, D→H, A→D}

在梯形ABCD中，AD∥BC,∠ABC=，AD=DC，点E、P在BC边上，点Q在

在梯形ABCD中，AD∥BC，AB=DC=AD=6，∠ABC=60°，点E，F分别在线段AD，DC上（点E与点A，D不重合），且∠BEF=120°，设AE=x，DF=y．

已知关系R(A,B,C,D,E,F,G),函数依赖集F为{AB→CF,AD→CE,AG→B,D→C,B→D},F的最小函数依赖集为_________。 A: {AB→C,AB→F,AD→C,AD→E,AG→B,B→D,D→C} B: {AB→F,AD→E,AG→B,D→C,B→D} C: {AB→F,AD→C,AG→B,D→C,B→D} D: {A→F,B→F,AD→E,A→B,G→B,D→C,B→D}