The haemocoel of an insect is actually a

In many arthropods,the head and thorax are fused to form a cephalothorax. However,in which of the following classes of animals is the body divided into head,thorax,and abdomen?

The largest animal phylum,which includes both oviparous and ovoviviparous species,is:

Which of the following characteristics is incorrect for an insect?

Book lungs are found in ......... .

Select the correct statement for phylum $Arthropoda$.