根据句意，在答题卡标有题号的横线上，写出括号内所给单词的适当形式。
The man kept remembering English words every day until he was in his _______ (forty).
—You’ve played Angry Birds for two hours. Don’t you think it’s boring?
—No, not at all. But we need to rest _______ (we) for a while now.
With the ________ (develop) of modern medicine, most eye problems can be treated and cured now.
She felt even _______ (ill) after working for another 2 hours.