There is only so much time in the day for answering letters.

白天只有这么多时间用来回信。

《柯林斯英汉双解大词典》

I feel terribly sorry for missing the chance of answering your letter in time.

非常抱歉，我没有及时回信。

youdao

If you have difficulty answering a question, leave it and move on to the next one—don't spend time tying yourself in mental knots over each question.

如果你回答一个问题时有困难，那就别管它，继续下一个——不要把时间都花在考虑一个问题上。

youdao

Seymour's supporters spent most of their time answering Republican charges.

VOA: special.2010.02.11

Those are questions that an identity thief would have a hard time answering if all the thief had to go on were the contents of your stolen wallet.

FORBES: Bring Lots Of I.D. Next Time You Buy A Car; Dealers Are Looking For Identity Thieves

But what seems noteworthy to me is not the downward blip in 2006 but the generally high level of Russian support for Israel over the past 9 years and the generally small number of Russians who will outright say they relate poorly towards it (the balance being made up by people who said they have a hard time answering).

FORBES: The Russian Public's Surprisingly Positive View of Israel

Most time is spent answering questions, doing exercises, working through problems, games and other activities that encourage active learning.

UNESCO: Introducing the TLSF Dissemination & Training Toolbox