SAN FRANCISCO CITY HALL TOUR
MONDAY----- FRIDAY
10:00a.m, 12:00 noon, 2:00p.m
All tours are 45 minutes to one hour
All tours sign in at
City Hall Decent Tour Kiosk
Located on the Main Floor
PEASE CALL AHEAD（预先）            Dr Carton B Goodlett Place
To schedule（安排） tours for schools       San Francisco. CA 94102
and groups of 8 or more               City Hall TTY (415) 554-7491
(415) 554-6139                      www.sfgov.org/cityhall

化简或计算：

（1）$\sqrt{\frac{1}{2}}$×$\sqrt{8}$；          

（2）（m﹣$\frac{1}{m}$）÷$\frac{m-1}{m}$．

24.李明同学在学习运动和力的知识后，对下列问题认识正确的是（    ）