下列运算正确的是[ ]
A.x5+x5=x10
B.x5·x5=x10
C.(x5)5=x10
D.x20÷x2=x10
答案:B
It's not good _______ your eyes to read _______ the sun. [ ]
A. for; in
B. to; under
C. for; on
D. of; under
钉道打锤不正,扫打,用撬棍扭打时八害道钉产生的原因。