---How ________ you spell the word “pen”?
--P-E-N, pen. [ ]
A. is
B. am
C. do
D. are
答案:C
油压千斤顶能力不大于100t,允许采用两人驱动。
伸缩缝是防止房屋受温度影响而产生不规则裂缝所预设的缝隙