Use appropriate sentence connectors in the blank spaces of the following text. Scientists have always wondered (a) ——— there is life anywhere out in the space. They have joined together in a major project called the communication with Extra Terrestrial Intelligence (b) ———— seeks to establish contact with any other living beings in the universe. (c)———-, they are beaming out radio signals into the space. It was thought (d) ————- there exists life on Mars. (e) ————- two viking spacecrafts (f)———— landed on Mars in 1976 did not provide much evidence of life there. The pictures sent by them showed (g) ———-- the Mars has a sky; (h)————, the sky is red instead of a blue one like ours. Its gravity is about half (i) ————-- strong (j) —————-- that of Earth. (k)————, the atmosphere is also much thinner than that of our planet. It has deserts, high mountains, canals, volcanoes, craters etc. as well as summer (l) ——————- winter. (m) —————--, there are no trees, (n) ————- life forms.