某芳烃(M = 120)质谱上于m/z 91和92处各显一强峰,下面哪种结构与此数据最为一致( )
某芳烃(M = 120)质谱上于m/z 91和92处各显一强峰,下面哪种结构与此数据最为一致( )
The average stress σm and stress amplitude σa of the alternating stress in the figure are respectively ( ).[img=239x154]17de8405f43ce66.jpg[/img] A: σm = 40MPa,σa = -120 MPa B: σm = -40MPa,σa = -40 MPa C: σm = 0MPa,σa = 120 MPa D: σm = -40MPa,σa = 80 MPa
The average stress σm and stress amplitude σa of the alternating stress in the figure are respectively ( ).[img=239x154]17de8405f43ce66.jpg[/img] A: σm = 40MPa,σa = -120 MPa B: σm = -40MPa,σa = -40 MPa C: σm = 0MPa,σa = 120 MPa D: σm = -40MPa,σa = 80 MPa
以下语句的执行结果是______。 ls=[120,'120',int('120'),12*10] print(ls.index(120),ls.count(120)) A: 13 B: 24 C: 03 D: 02
以下语句的执行结果是______。 ls=[120,'120',int('120'),12*10] print(ls.index(120),ls.count(120)) A: 13 B: 24 C: 03 D: 02
以下语句的执行结果是______。ls = [120,'120',int('120'),12*10]print(ls.index(120),ls.count(120)) A: 1 3 B: 0 3 C: 0 2 D: 2 4
以下语句的执行结果是______。ls = [120,'120',int('120'),12*10]print(ls.index(120),ls.count(120)) A: 1 3 B: 0 3 C: 0 2 D: 2 4
可见光波长在( ) 范围内。 A: 3—8µm B: 4—120µm C: 0.4—0.76µm D: 0.15—4µm
可见光波长在( ) 范围内。 A: 3—8µm B: 4—120µm C: 0.4—0.76µm D: 0.15—4µm
1525.正方形每条边的测量结果均为30±0.005m,则周长为()m。 A: 120±0.010 B: 120±0.020 C: 120±0.030 D: 120±0.040
1525.正方形每条边的测量结果均为30±0.005m,则周长为()m。 A: 120±0.010 B: 120±0.020 C: 120±0.030 D: 120±0.040
已知集合M={﹣1,1},,则M∩N=[ ]
已知集合M={﹣1,1},,则M∩N=[ ]
已知集合M={x|},N={},则M∩N=[ ]
已知集合M={x|},N={},则M∩N=[ ]
下面代码的输出结果是li = ["hello",'se',[["m","n"],["h","kelly"],'all'],123,446]print(li[2][1][1]) A: n B: h C: m D: kelly
下面代码的输出结果是li = ["hello",'se',[["m","n"],["h","kelly"],'all'],123,446]print(li[2][1][1]) A: n B: h C: m D: kelly
下列代码的输出结果是( )。li = ["hello",'se',[["m","n"],["h","kelly"],'all'],123,446]print(li[2][1][1]) A: h B: kelly C: n D: m
下列代码的输出结果是( )。li = ["hello",'se',[["m","n"],["h","kelly"],'all'],123,446]print(li[2][1][1]) A: h B: kelly C: n D: m