吕思勉曾就中国历史的研究从主要对象和方法两方面做过论述，请把这个研究框架写成一段话，要求内容得当，表述准确，语言连贯，不超过60字。

下列句子中，没有语病的一项是（     ）

在下面一段文字横线处补写恰当的语句，使整段文字语意完整连贯，内容贴切，逻辑严密。每处不超过15个字。

       中国人的餐具主要是用竹子、木头制造的，是植物性的，____，如大米、玉米、小麦和小米等，所以对这些食物的味道影响不大。而且，由于是素食，氨基酸尤其是谷氨酸不多，香味也不大，所以对食物的味道影响不大。但西方人吃动物性食物较多，____，如此才能操控、驾驭食物，如切割动物性食物。而且，由于动物性食物的谷氨酸较多，吃起来比较香， ____，因此用金属筷子、刀叉吃饭，会让人感到食物更咸、味道更浓。

    My holiday is coming.Yesterday I asked my American friends about the best way to travel around the United States. They said it was best to travel by 1 and gave me the 2.

    To fly, of course, is the fastest way, but one can't see anything during a 3 except the blue sky and white clouds. So it is not very interesting for one who wants to see the 4.Besides, the plane ticket is very 5.

    To travel by train is 6, because passengers can walk and buy food and drinks on a train. They can also see cities and the country through the windows. But trains don't leave or 7 at a place every day, and don't go to many cities.

    To travel by bus is easy, cheap and convenient, though not so fast as travelling by plane or so 8 as by train. You can find buses almost in every city. That makes travel arrangement easy.

    I take their 9.Now I have decided to go on an interesting 10 by bus to the east coast.