According to the passage, which of the following can cause buildings to “sink…

Concept: A detail question of the “according to the passage” type is settled by the text alone — never by outside knowledge, and never by whichever process sounds most destructive. The reading method is fixed:

1. Locate the sentence that states the exact effect the question quotes.

2. Read the cause the writer ties to that sentence — the link is usually carried by a pointer phrase such as “under these conditions”, “this”, or “because of that”.

Application: Applying that method to this passage:

1. The stated effect closes the passage — “Buildings sometimes sink out of sight or fall down like a row of dominoes under these conditions.”

2. The pointer “under these conditions” looks back at the sentence immediately before it: “Water-saturated soil can liquefy when shaken.”

3. So the cause the passage attaches to buildings sinking out of sight is the shaking of water-saturated soil, whose grains lose contact with one another so that the ground briefly behaves like a fluid and can no longer carry the weight standing on it.

Contrast: the other processes named appear in the passage, or in the subject, in different roles.

• Tsunamis — the 2004 Banda Aceh earthquake and tsunami opens the passage as a measure of scale, with a toll above 230,000 and damage reaching as far as Africa; the sinking of buildings is tied by the writer to the behaviour of the ground beneath them, not to wave action.

• Creep — the passage defines creep, or seismic slip, as fault movement that is gradual and relatively smooth and may be undetectable to a casual observer; it is contrasted in the same paragraph with the sudden jerk that follows when friction holds the rocks.

• Soil expansion — the ground conditions the passage discusses are soft landfill, poorly consolidated soil, and water saturation; the swelling of soil as it absorbs moisture is a process the text never introduces.

Cross-check: the same paragraph explains why Kobe and Mexico City, parts of which stand on soft landfill or poorly consolidated soil, suffer the greatest damage — throughout, the passage locates the worst earthquake damage in the condition of the ground a city stands on rather than in the shaking alone. Answer: shaking of water-saturated soil.