致病力最强的二氧化硅粉尘微粒的直径是
未知类型：{'options': ['[tex=4.571x1.286]rjkAEvMUYMBj863gEFxZng==[/tex]', '[tex=4.071x1.286]seWJnDlhvqT5OP0Wu3vwYA==[/tex]', '[tex=4.071x1.286]xksW5GX80Sz/YiT8zF4L9w==[/tex]', '[tex=5.5x1.286]phzgwv0FosvR6kppuvG/vYclj4Wyzu6UJKFBp9vbU+o=[/tex]', '[tex=4.571x1.286]TVZS2we4I3rQZ7UKMVZLiA==[/tex]'], 'type': 102}
未知类型：{'options': ['[tex=4.571x1.286]rjkAEvMUYMBj863gEFxZng==[/tex]', '[tex=4.071x1.286]seWJnDlhvqT5OP0Wu3vwYA==[/tex]', '[tex=4.071x1.286]xksW5GX80Sz/YiT8zF4L9w==[/tex]', '[tex=5.5x1.286]phzgwv0FosvR6kppuvG/vYclj4Wyzu6UJKFBp9vbU+o=[/tex]', '[tex=4.571x1.286]TVZS2we4I3rQZ7UKMVZLiA==[/tex]'], 'type': 102}
举一反三
- 已知向量[tex=5.643x1.286]2HKJ+34uBXu3DbhHKLrGKQ==[/tex]，[tex=5.5x1.286]YxBSYjqnkOglv+HFGSt5XQ==[/tex]，[tex=5.5x1.286]A94SJl+klKm/VJjddX9d+A==[/tex]，求：(1)[tex=6.786x1.286]TkoPO9ooAPZE8kDX0Ksl4/ZY708Rsy7drjUyImg7U8k=[/tex]；(2)[tex=4.071x1.286]wLCgIV9Inyr6HA4KUwzc3o8dW+QaqtN8Vh4Ic4T9aKo=[/tex]；(3)[tex=4.571x1.286]wLCgIV9Inyr6HA4KUwzc3oQ8chRS+v5X/lEvFUZAFCU=[/tex]；(4)[tex=6.857x1.286]+8TpnXhNjVA8ASM37C57bPO2VHJACzhdrkBhWbOw8pepTAtBRrxQ67nhgbDgIjYW[/tex]．
- 下列方程中是一阶微分方程的是[input=type:blank,size:4][/input]. 未知类型：{'options': ['[tex=8.0x1.571]SnLzj4UlSfnGqNtEzxfZSuZwslGsWxsvP2Y+yf7H578Vefe1Ol/nJT135DjkdnSNNikL3arAj80BjvPHaHCDiA==[/tex]', '[tex=10.571x1.571]JR4yrHJRIZfJXwhFSObwrfajFnWUvXzM/YiA3M6aDKuVBZ8I+7v5iXTXdA3E6Rm4vOE2BCfPwFP2rmRygXKEUDk1qLsNDCJ2p8GEbfCSr2s=[/tex]', '[tex=5.643x1.357]m0sKckxx+jZ9iltApBtB23TBISIOx/g0judcsS+akNFZrUNCq3g+BIVQwGbQEh/C[/tex]', '$y^{(4)}+5 y^{\\prime}-\\cos x=0$'], 'type': 102}
- [tex=1.857x1.0]1FVfIOJf7ISeQGf+8HT7Iw==[/tex]尿素的合成需消耗[tex=2.214x1.286]iLZ8dFzDhyDszs4Q6Iairw==[/tex]摩尔数是 未知类型：{'options': ['2', '3', '4', '5', '6'], 'type': 102}
- 能产生正弦波振荡的必要条件是（） [br][/br] 未知类型：{'options': ['[tex=4.071x1.5]ZHMXiER8ZaDxxsVT/bVH3+lsP/UBZFV5rlr3gMkTWAo=[/tex]', '[tex=3.786x1.5]X/dAPQG629Xxhzt6x5zsxXQwhBAICzqMGDmsrceVcnk=[/tex]', '[tex=3.786x1.5]X/dAPQG629Xxhzt6x5zsxUy/rK6N2R3d20utEgygqgQ=[/tex]', '[tex=6.214x1.5]4p1ea1IYayd4Z8XNUjoBPD5L7ZWp5rKrXhXmNG5YIgo=[/tex]'], 'type': 102}
- 设I(x):x是整数;N(x):x是负数;S(x，y):y是x的平方命题“任何整数的平方非负”可表示为谓词公式 未知类型：{'options': ['[tex=11.929x1.357]Ab8zVcSaawMRd84sw7i/JAhyPtafOzIiYwAO+plGfU5YAO/QV3YAB0GXAXRhZ7CliwQzjDdB7FbEZsDooWfNcKY5XHTFYR6Idofr8S7Wax4=[/tex]', '[tex=11.214x1.357]Vs8Vcw/zPN7kvQW5F7NycC9PlK+v4vkWJ4hyjFXkOftd5yicp99G5Tnp+KzILEwlHDVGwqo5md6rK5TfGKT6pg==[/tex]', '[tex=11.214x1.357]Ab8zVcSaawMRd84sw7i/JPLc5lkPb0vCB3HAoQdCvLgUiouuuSbyQIQ62rJKADX6FQeTBBqnQa6q/6Qzw2KRYw==[/tex]', '[tex=10.929x1.357]mX5PRaABESRf9QDOAojNZuqee9gfCLdnz+se+AlyZp5SHDOcNaBoGKl0MgSjkAb89Uw7a1sL8h1OT0gFb59yAg==[/tex]'], 'type': 102}