为王明写一封感谢信，内容为：感谢史密斯教授在期末这段特别繁忙的时间同意为你写推荐信，如能拿到奖学金，会立即奉告。并随信附上一个给该大学的研究生院的邮资已付的信封。
Words for reference：
奖学金scholarship
奉告inform
随信附上enclose
邮资postage

A．childish
B．hard
C．no enjoyment
D．worthwhile

A．the sun is our ultimate source of energy
B．the tiny fraction of the sun’s energy which we use is used indirectly
C．we are making progress toward utilizing the solar energy fully
D．one device using solar energy directly has been developed