语法题，请教大虾

1。（Besides providing）clues to the nature of atoms, (mineral analysis) allows (to speculate geologists) about the (ancient) Earth.   答案是C，何解

2。Tom was elected (president) last semester, (but) he (has since devoted) (few) of his spare time to his job. 答案D，why???

1, allow sb to do sth

2, little of his time--- unacountable

few of my friends -- acountable

Tom was elected (president) last semester

被动后怎么可以加宾语呢？！这个president没错吗？！那要怎么解释呢？！

求解！谢谢！

since在这里的词性是副词，意思是"自从那是"。