latch与register的区别，为什么现在多用register？

If the storage type of a variable is , the compiler allocates memory only when the variable is referred?? register or static|extern or register|auto or register|auto or static

to register

‏In a standard symphony orchestra, the cello is the only instrument providing low-register harmony, also many orchestral pieces require cello soli or solos.‏‏‏

instruction register

Mercury freezes if it is cooled to＿. A: a too low temperature B: too low temperature C: a low too temperature D: too low a temperature

The champion boxer fought bravely to defend his title, but was finally by a knockout blow. A: laid low B: lay low C: lie low D: lying low

digitalRead(KEY)==LOW语句中lOW表示（ ）。

The aphotic zone (bottom of the ocean) will have ____ and ____ while the photic zone (surface of the ocean) will have ____ and ____. A: low temperature, low salinity; high temperature, high salinity B: low temperature, high salinity; high temperature, low salinity C: high temperature, high salinity; low temperature, low salinity D: high temperature, low salinity; low temperature, high salinity E: both have equal temperature and salinity

ENUM类型的字段level定义为（LOW、MIDDLE、HIGH），ORDER BY level asc的顺序是 A: HIGH、LOW、MIDDLE B: LOW、MIDDLE、HIGH C: MIDDLE、LOW、HIGH D: HIGH、MIDDLE、LOW