A:where Alice had put
B:where had Alice put
C:where Alice has put
D:where has Alice put
某四冲程汽油机在正常工作时,每秒完成40个冲程,则它每秒对外做功 ____ 次,飞轮转过 ____ 圈.
下列有关溶液的认识中,错误的是 ( )