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。
