A midday nap can not only ________ brain to its full awakeness best but also raise brain power beyond what it would have been without some shut­eye.

Although Jane agrees with me on most points , there was one on which she was unwilling to      .

The whole book ________ twelve units, ________ two that are mainly for revision.

I set out to ___________ Liu Ming.

Although he _______ the danger to his own health, he found it difficult to quit smoking.