Tom very hard to learn maths, but he was still not good at it.

I haven’t been to an aquarium.–________.

e me, sir. Can you spare me a dollar ________ I can buy this book—Sure, no problem.

下列各句子中，加点的成语使用恰当的一项是

_____the society developing very fast, it’s quite necessary that we should have a good knowledge of English and computers[ ]