有机物①C2H6 ②C2H4 ③C2H2 ④C6H6它们分子中的碳碳键键长由大到小排列顺序正确的是
| A．①＞②＞③＞④ | B．①＞④＞②＞③ |
| C．④＞②＞①＞③ | D．④＞①＞②＞③ |
相关试题
All the dishes in this menu, ______ otherwise stated, will serve two to three people. 
| A．as | B．if | C．though | D．unless |
The children loved their day trip, and they enjoyed the horse ride ______.
| A．most | B．more | C．less | D．little |
Progress______ so far very good and we are sure that the work will be finished on time.
| A．was | B．had been | C．has been | D．will be |
Charles was alone at home, with_______ looking after him.
| A．someone | B．anyone | C．not one | D．no one |
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