Complex sentence: The exploitation teams under the Russian Alsos, headed by Lavrenij Beria's deputy Colonel General A. P. Zavenyagin, were composed of scientific staff members, in NKVD officer's uniforms, from the bomb project's only laboratory, Laboratory No.2, in Moscow.
Split into simpler sentences: The exploitation teams were under the Russian Alsos and they were headed by Lavrenij Beria's deputy, Colonel General A. P. Zavenyagin. These teams were composed of scientific staff members, in NKVD officer's uniforms, from the bomb project's only laboratory, Laboratory No.2, in Moscow.