The Nuclear Security Summit is an initiative of Mr. Obama, considers nuclear terrorism to be one of the greatest threats to international security.

At present, one of the best ways to study is working in groups.—More chances _______ to students to learn from each other.

63 He was elected_______of the footballteam last year

Wish you a pleasant journey!—-Thanks ! I’ ll give you a _________as soon as I arrive in Paris.

The kid is only three, but he can say________English words.