Which zone is a system-defined zone？（） A: null zone B: trust zone C: untrust zone D: management zone

In zone settling, sludge surface is between _____ . A: clean water zone and isoconcentration zone B: isoconcentration zone and transition zone C: transition zone and compression zone

The distance of the intimate zone is ________________, the personal zone is ____________, the casual zone is ___________, the public zone is _______________.

Wuzhou lies in _______. A: the tropical zone B: the cold-temperate zone C: the subtropical zone D: the temperate zone

The unsaturated zone (vadose zone) is the area above the zone of saturation.

For a material item to be classified as an extraordinary item on the income statement, the item must be: （） A: current and unusual in frequency. B: probable and infrequent in nature. C: unusual in nature and infrequent in occurrence.

Psychologists have identified four zones of interaction for Americans: the __________ zone, the __________ zone, the _______ zone, and the _______ zone.

According to gravity models, the number of trips produced in zone i and attracted to zone j depends on A: Total number of trips produced in zone i B: Total number of trips attracted to zone j C: Total number of trips produced in zone j D: Total number of trips attracted to zone i

Vygotsky refers to “the distance between the actual development level and the level of potential development” as ( ) A: zone of proximal learning B: zone of self-achievement C: zone of proximal development D: zone of scaffold learning

Running water, although infrequent, nevertheless does most of the erosional work in deserts.