据统计，自武昌起义至1913年底，国内新成立的公开团体有682个，其中政治类团体312个，主要集中在京、津、沪、宁、穗等地，而京、沪两地又占1/2以上。出现上述现象的主要原因是（  ）

十一届三中全会是新中国成立以来党的历史上具有深远意义的伟大转折．这次会议上确立的党在新时期的思想路线是（　　）

“遗传学之父”孟德尔通过豌豆实验，发现了遗传的两大基本规律，即基因的分离定律和基因的自由组合定律．

（1）选择豌豆作为实验材料，是孟德尔获得成功的原因之一，请用简要的文字说明自然种植下的豌豆大多是纯合子的原因．____ 

（2）通常情况下，高茎豌豆和矮茎豌豆杂交，F₁全为高茎，F₁自交，F₂中高茎和矮茎比接近3：1．现有两株矮茎豌豆品种杂交，F₁却全为高茎．让F₁随机交配产生了192株后代，其中107株为高茎，85株为矮茎．

问：①F₂表现型的分离比接近____ ．

②若按孟德尔遗传定律分析，控制该对性状至少涉及____ 对等位基因，两株亲本矮茎豌豆可能的基因型是____ ．（基因用A和a、B和b、C和c …表示）

    Singapore's public transport system 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 cars for $15, you can ride the trains and buses as you like.

    If you need more information, just call Transit Link on 1800 525 7333.

    BUSES

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

    If you need help, just call Transit Link on 1800 525 7333.

    TAXIS

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

    RENTAL CARS

    Driving in Singapore is a pleasure and if you liked 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 + 65 6737 1668.