One immediate cause of a decrease in the rate of photosynthesis is a reduction in the availability of A carbon dioxide
B.
carbon monoxide
Chydrogen
D. nitrogen

A Carbon Dioxide

Explanation:

If CO2 is not availabe photosynthesis will not take place.

Hydrogen, Nitrong and CO(carbon monoxide) are not needed at all for photosynthesis

answer'(basidium)the spore--bearing structure of a basidiomycete is called a basidiocarp; ///

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.