Retrofitting houses to use less energy should be a no-brainer for homeowners.（1）time,money spent on ways to reduce heat loss from draughty houses should produce a（2）return in lower fuel bills.In practice,many are cautious.Some improvements,such as solid-wall insulation and solar panels,can take over 25 years to（3）their initial cost.Few owners are willing to wait that long by then many are likely to have（4）and moved on Several governments have started finance schemes designed to（5）this problem.Since 2008 PaCE programmes have offered American homeowners loans to（6）improvements,repaid through higher local taxes on the property,（7）it belongs to.In Britain,the Green Deal offers loans over a 25-year period,with repayments added to energy bills.Countries including France and Canada have similar（8）In theory,these schemes should boost investment in common energy-saving measures,such as extra insulation and new boilers,（9）the first owner does not have to pay all the costs in advance But enrolment rates have（10）,according to Sean Kidney at the Climate Bonds Initiative,a think tank.In Britain,just 1%of those assesseed for the Green Deal have signed up.In Berkeley,California,home of the first PACe scheme,the（11）rate is similarly low.Homeowners are（12）chiefly because the interest rates on the loans look high.The Green Deal charges 7%;some PaCe schemes a hefty 8%.As these rates are fixed for decades,they will（13）look unattractive when（as now）short-term interest rates are low Many people also（14）they will save enough on their energy bills to cover the repayments Fc or instance（15）in britain that installing loft insulation can cut energy bills by 20%have been dented by a government study that found it（16）gas consumption by only 1.7%on average.Others fear that green loans may reduce the value of their home.In America,firms that underwn mortgages are（17）PACE loans Green loans have not been a failure everywhere.Around 250,000 households in Germany（18）for them each year.They do so（19）they need pay only 1%interest on them each year thanks to an annual public subsidy of 1.5 billion.Whether that is a（an）（20）use of taxpayers’money is another question（12）选？
A.unhappy
B.unimpressed
C.unsurprised
D.unsustainable