If you have the grain going the wrong way the paper will ripple, the fold will not be clean and the book will want to close itself.

如果把纸的纹路弄反了，纸就会起皱，折边也不整齐，书还总是会自己合上。

youdao

Fold the letter AD put it into the envelope and then close it.

把信折叠起来并且把它放进信封并且关上信封。

youdao

The changes of the flow condition and velocity of the nail-fold microcirculation were in close correlation with the increase of blood viscosity and the severity of the disease.

甲皱襞微循环流态和流速改变与病情和血液粘度增高程度有一定平行关系。

youdao

Still in concept stage, the steering wheel features two handles that close fully and fold away into the dashboard, which the company says significantly improves driver comfort and accessibility.

FORBES: Ready for a Folding Steering Wheel?

At the time of writing, all the major Euro countries are in crisis, with Germany close to joining the fold, with growth set to halve next year (assuming Euro-zone problems get no worse).

FORBES: Congratulations, But Can The World Outside Europe Live With The EU and Euro?

That's close to a four-fold increase over the previous year, 2004.

NPR: Iran Most Active in Terrorism, Says State Dept.