美國(guó)副總統(tǒng)官邸準(zhǔn)備加強(qiáng)安全裝置。 "The Vice President's official residence is getting a $1.7 million security upgrade," 副總統(tǒng)官邸要進(jìn)行耗資170萬(wàn)美元的保安系統(tǒng)升級(jí)。市場(chǎng)調(diào)查顯示, "Many customers are putting off plans to upgrade their cell phones during the economic downturn," 經(jīng)濟(jì)不景氣,使很多顧客推遲手機(jī)升級(jí)的計(jì)劃。好的,今天我們學(xué)習(xí)的詞upgrade...