1. crack down on （厳しく取り締まる）
= The police have been cracking down on drug dealing.
2. vie for（～を得ようと競い合う）
= Several boys are vying for her attention.
3. lash out at（～を厳しく非難する）
= The prime minister lashed out at the opposition.
4. tap into（（資源などを）利用する）
= We can tap into the wealth of information on the Internet.
5. toy with（～を漠然と考える）
= She is toying with the idea of studying abroad.
6. taper off（次第に弱まる）
= After a while, the rain began to taper off.
7. pore over（～を熟読する、じっくりと見る）
= He spent hours poring over the report.
8. iron out（解決する）
= They have finally ironed out the bugs in the software.