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Cells cannot remain alive outside certain limits of temperature and much narrower limits mark the boundaries of effective functioning. Enzyme systems of mammals and birds are most efficient only withi
Review of Units1-6 [00:03.81]2a Listen and number the pictures[1-4]. [01:11.89]2b Read the sentences below. [01:17.45]Then listen again and circle T(for true)of F(for false). [01:25.71]The boy is Nick Smith. T F [01:42.35]Nick doesn't like his class.
Review of units 1-6 [00:04.70]3a Listen to the four conversations. [00:10.87]Match the conversations with the correct pictures. [02:18.03]3b Listen again and follow the instructions next to the pictures. [04:26.79]Review of units 1-6 to expressions [
Review of units 7-12 [00:03.89]3a Listen to the four conversations. [00:09.85]match the conversations with the correct pictures. [02:37.31]Listen again and follow the instructions next to the pictures. [05:05.06]Review of units 7-12 [05:14.02]topping
Some bacteria have adapted to super cold environments for millions of years. And scientists have isolated some of the essential genes that allow bacteria to tolerate their harsh living conditionsbecause these same genes might help in the creation of
Review of units 11-15 [00:04.78]2a Listen to the four conversations. [00:10.66]Match the conversations with the correct pictures. [04:08.56]2b Listen again and follow the instructions above next to the pictures. [08:11.05]Review of units 11-15 [08:19