题目

质粒是基因工程中最常用的运载体，它存在于许多细菌体内。质粒上有标记基因如图所示，通过标记基因可以推知外源基因（目的基因）是否转移成功。外源基因插入的位置不同，细菌在培养基上的生长情况也不同，下图是外源基因插入位置（插入点有a、b、c），下列有关叙述正确的一组是       A．插入位置a；细菌可在含青霉素的培养基上生长B．插入位置b；细菌可在含四环素的培养基上生长C．若要细菌在含青霉素和四环素的培养基上均能生长阅读理解。      Not long ago, China decided to build a bridge to link Zhuhai, Hong Kong and Macao. People will finishbuilding it in 2016. It will be the world's longest sea-crossing bridge!     The Y-shaped bridge is about 50 kilometers altogether. 35 kilometers of it will be over water.      Officials say the bridge we use will last in good condition for 120 years. It can handle big earthquakes as well as strong winds. And it will be all right even if it is hit by a 300,000-ton ship.     With six car lanes, a car can go as fast as 100 km per hour on the bridge. It will only take 30 minutes to drive from Zhuhai or Macao to Hong Kong.      Some people worry that the building of the bridge will pollute the sea and hurt sea animals. Officialssay they will protect the ocean.      China hopes that the bridge can bring the mainland, Hong Kong and Macao closer. Building the bridgewill cost about ￥73 billion. Hong Kong, Macao and the mainland will share the cost. 1. It will take China ______ years to build the bridge. [     ]A. 3B. 6 C. 10D. 14 2. The shape of the bridge is like the letter "______". [     ] A. "H" B. "M" C. "Y" D. "V" 3. The bridge is about ______ long. [     ]A. 50 kilometersB. 36 kilometers C. 100 kilometers D. 120 kilometers 4. What do some people worry about? [     ] A. The bridge is too long. B. It will take a long time to build it. C. Officials will protect the ocean. D. The building of the bridge will pollute the sea and hurt sea animals. 5. Who will share the cost of the building of the bridge? [     ]A. Hong Kong B. Macao C. The mainland D. A, B and C