如图，小明用长为3m的竹竿CD做测量工具，测量学校旗杆AB的高度，移动竹竿，使竹竿与旗杆的顶端C、A与O点在一条直线上，则根据图中数据可得旗杆AB的高为____m．

小明用自制的电磁铁来研究它的磁性与哪些因素有关．实验器材：两个相同大小的大铁钉、一些漆包线、开关、电源、滑动变阻器、一些回形针和电流表等．在实验中，用漆包线绕制横截面和紧密程度相同的三个线圈，其中两个线圈插入铁钉，另一个线圈内无铁钉．按如图电路进行实验，实验记录的数据如下表：由以上实验表明，电磁铁的磁性强弱与哪些因素有关（　　）

    Singapore's public transport system(公共交通系统)is one of the best in the world, so you should have no problem finding your way around like a local. There are three main forms of public transport that you would find in any other major city--trains, buses and taxis.

TRAINS

    Trains run from 6: 00 am to midnight. Single trip tickets start at 80 cents. If you buy an EZ-link card for MYMI5, you can ride the trains and buses all you like.

    If you need more information, just call Transit Link on 1800 767 4333.

BUSES

    There are several bus services in Singapore and fares start at 80cents. Be sure to always ask the driver the cost of your ticket as he cannot give changes.

    If you need help, just call Transit Link on 1800 767 4333.

TAXIS

    There are three main taxi companies--city Cab(6552 2222), Comfort(6552 1111) and Tibs (6552 8888). Booking can also be made easily by calling the numbers listed above.

RENTAL CARS

    Driving in Singapore is a pleasure and if you like to travel at your own pace, renting a car is a good choice. Renting takes away the hassle of getting to places around Singapore. Just sit back and enjoy the city. It also means you'll get to see a lot more that a train or a bus won't let you see.

    For car rental, call Avis on +656737 1668

根据课文《难忘的一课》的内容填空

    “还有什么别的话比这句最简单的话更足以表达我此时的全部感情呢？”这是一句____句，意思是说：____。