Problem: Though the true dimensions of species diversity remain uncertain, estimates range from 2.67.8 million species with a mean of 5.5 million. This probably represents less than 20% of all species on Earth[citation needed], and with only about 20,000 new species of all organisms being described each year, most species likely will remain undescribed for many years unless species descriptions increase in rate. About 850,0001,000,000 of all described species are insects. Of the 24 orders of insects, four dominate in terms of numbers of described species, with at least 3 million species included in Coleoptera, Diptera, Hymenoptera and Lepidoptera. A recent study estimated the number of beetles at 0.92.1 million with a mean of 1.5 million.
For many years to come, most insect species will remain as what?
The answer is the following: undescribed

Problem: DDT, sprayed on the walls of houses, is an organochlorine that has been used to fight malaria since the 1950s. Recent policy statements by the World Health Organization have given stronger support to this approach. However, DDT and other organochlorine pesticides have been banned in most countries worldwide because of their persistence in the environment and human toxicity. DDT use is not always effective, as resistance to DDT was identified in Africa as early as 1955, and by 1972 nineteen species of mosquito worldwide were resistant to DDT.
Is DDT 100% guaranteed to work?
The answer is the following: DDT use is not always effective

Problem: In chemical terms, the difference between hardwood and softwood is reflected in the composition of the constituent lignin. Hardwood lignin is primarily derived from sinapyl alcohol and coniferyl alcohol. Softwood lignin is mainly derived from coniferyl alcohol.
In addition to coniferyl alcohol, what other alcohol is in hardwood lignin?
The answer is the following: sinapyl

Problem: A band of Middle Devonian limestone runs west to east from Cremyll to Plymstock including the Hoe. Local limestone may be seen in numerous buildings, walls and pavements throughout Plymouth. To the north and north east of the city is the granite mass of Dartmoor; the granite was mined and exported via Plymouth. Rocks brought down the Tamar from Dartmoor include ores containing tin, copper, tungsten, lead and other minerals. There is evidence that the middle Devonian limestone belt at the south edge of Plymouth and in Plymstock was quarried at West Hoe, Cattedown and Radford.
What location north of the city possesses granite?
The answer is the following:
Dartmoor