Which of the following best describes the formation of “desert pavement”?
A: alluvial fans are eroded to form inselbergs with flat, angular rocky surfaces
B: runoff and deflation carry off the fine particles of silt and clay, leaving coarser particles behind
C: groundwater in an alluvial fan evaporates, leaving behind a surface layer of hard-baked mud and boulders
D: deflation removes the coarse fragments leaving behind a layer of fine sediment (loess and mud)
A: alluvial fans are eroded to form inselbergs with flat, angular rocky surfaces
B: runoff and deflation carry off the fine particles of silt and clay, leaving coarser particles behind
C: groundwater in an alluvial fan evaporates, leaving behind a surface layer of hard-baked mud and boulders
D: deflation removes the coarse fragments leaving behind a layer of fine sediment (loess and mud)
举一反三
- Every year hundreds of thousands of migrant workers move to big cities, ______ their care-hungry old parents and young kids. A: leaving behind B: leaving aside C: leaving off D: leaving for
- There is no sense in ______important decisions ___inexperienced people. A: tracking B: tracing C: leaving behind D: leaving ... to
- With nothing ______ behind, he felt _______. A: left; relieved B: leaving; relief C: left; relieving D: leaving; relieved
- The particles are put into a vacuum with a/an ______ amount of heat, which turns the ice into steam, leaving the ground particles dry and ready for use. A: abstract B: minimal C: symbolic D: potential
- The consequences of uneven water distribution include ( ) A: "mud ball" or "mud cake" will form, which can cause a short-circuiting phenomenon during filtration B: the filter media may break during filtration and backwash periods C: backwash pipes may be destroyed D: The particles of the local support layer will move and mix with the filter media, and the filter media will run off under this situation if a large amount of uneven backwash water come through