2013年3月，******首次出访的国家中，既跨两大洲又跨东西半球的是（   ）

       A hot dog is one of the most popular American food. It was named after frankfurter, a German food. You may hear “hot dog”1in other ways. People sometimes 2“hot dog” to express pleasure(快乐). For example, a friend may ask 3 you would like to go to the cinema. You might say, “Great. I’d love to. ” Or, you could say,”4! I'd love to go.” People 5use the expression to describe someone who is a “show-off”, who tries to show everyone else how 6he is. You often hear such a(n)7called a “hot dog”. He may be a basketball player, for example, who 8the ball with one hand making a(n) 9 catch seem more difficult. You know he is a “hot dog” because when he makes such a catch, he bows(鞠躬) to crowd, hoping to10their cheers.

The movie covers all of Chinese history. It is _________ worth seeing again.

某动车组列车以平均速度v从甲地开到乙地所需的时间为t，该列车以速度v₀从甲地出发匀速前进，途中接到紧急停车命令紧急刹车，列车停车后又立即匀加速到v₀继续匀速前进，从开始刹车至加速到v₀的时间是t₀（列车刹车过程与加速过程中的加速度大小相等），若列车仍要在t时间内到达乙地，则动车组列车匀速运动的速度v₀应为（   ）