用括号里所给词的适当形式填空。每空一词。

小题1:More and more people pay attention to food       (safe) now.

小题2:It seems that the woman is in her      ( thirty ).

小题3:My uncle likes reading. He often buys       (week) newspapers to read.

小题4:My favourite programme Yang Lan One on One usually begins with a       (discuss).

小题5:The Tigers in India are        (appear) faster than pandas at present.

A、B、C、D四种有机物的碳原子数目相同。标况下烃A对氢气的相对密度是13；烃B跟HBr反应生成C；C与D混合后加入NaOH溶液并加热可生成B。则D为 [ ]

A．C₂H₅Cl

B．C₂H₄Cl₂

C．C₂H₆

D．C₂H₅OH