• Even homeowners whose yards do not have water-conserving landscapes can conserve water by installing water-saving devices in their homes.
• A conventional landscape generally requires a much greater expenditure on fertilizer and herbicide than does a water-conserving landscape.
• A significant proportion of the residents of the city live in buildings that do not have yards.
• It costs no more to put in water-conserving landscaping than it does to put in conventional landscaping.
• Some homeowners use more water to maintain their yards than they use for all other purposes combined.

我的理解如下，刚刚开始复习，看到你的题顺便做下，仅供参考.

Criticism:For most people with yards, thesavings from converting to a water-conserving landscape cannot justify theexpense of new landscaping, since typically the conversion would save less thantwenty dollars on a homeowner’s yearly water bills.
(disagree to convert to water-conserving landscap, concern focus on economically )

Which ofthe following, if true, provides the best basis for a rebuttal of thecriticism?
(要反对Criticism，也就是说要找那个方面water-conserving 比conventional省钱)

• Even homeowners whose yards do not have     water-conserving landscapes can conserve water by installing water-saving     devices in their homes.
• A conventional landscape generally requires a much     greater expenditure on fertilizer and herbicide than does a     water-conserving landscape.（conventional landscape在fertilizer&herbicide方面比较贵，water-conserving 便宜）
• A significant proportion of the residents of the     city live in buildings that do not have yards.
• It costs no more to put in water-conserving     landscaping than it does to put in conventional landscaping.（water-conserving和conventional需要的钱一样，不能说明water-conserving就好）
• Some homeowners use more water to maintain their     yards than they use for all other purposes combined.