a nuclear umbrella的用法和样例：
- PRC was also developing a nuclear weapons program despite Khrushchev's preference to keep Beijing under the Soviet nuclear umbrella.
- "Last week, Clinton talked in vague terms about the creation of a nuclear umbrella to protect the Mid East alies Mideast allies against the a possible Iranian nuclear attack.
- Last week, Clinton talked in big vague terms about the creational creation of a nuclear umbrella to protect medist x Mideast allies against a possible Iran's Iranian nuclear attack.
- They decided to establish a nuclear power station.
- One who prepares a nuclear weapon for release.
- An atomic or a nuclear bomb. Used with the.