He fell asleep immediately last night; he must ________ (be) very tired.
have been
暂无解析
he teacher told them since light ________ (travel) faster than sound,lightning ________ (appear) to go before thunder.
Ishallneverforget________(meet)thelatePremierZhouduringhisinspectionofourfactory.
________(catch)intherain,hewaswettotheskin.
Comrade Li ________ be in Beijing because I saw him in town only a few minutes ago.
To succeed in a scientific research project ________.
