原核细胞型微生物不包括
A.立克次体B.病毒C.放线菌D.螺旋体E.支原体
参考答案:B
解析:病毒没有细胞结构,属于非细胞型微生物。
Swimmers must be very strong in order to build up speed because of the high resistance of the water. Runners, ____, must struggle against the heavy resistance of the air and ground.
A.generally
B.similarly
C.naturally
D.probably
偏心受拉构件的受弯承载力()。
A.小偏心受拉时随着轴向力的增大而增大
B.大偏心受拉时随着轴向力的增大而增大
C.大偏心受拉和小偏心受拉时均随轴向力的增大而增大
D.大偏心受拉和小偏心受拉时均随轴向力的减小而增大