题目

下列能源中，不会对环境造成污染而且取之不尽的是（ ） A．石油     B．天然气     C．氢气     D．太阳能 答案：D—Do you believe that American flags are made China?—Yes, I do. And you can see they are made silk.A. in; from B. from; inC. of; in D. in; of