Pls pls pls help me pls Franco has a rock in his collection that is very smooth and glassy. He knows that the rock was formed by lava that cooled very quickly after a volcanic eruption. Which kind of rock does Franco have?

Group of answer choices

concrete

igneous

metamorphic

sedimentary

Benji is writing some observations of different samples in his mineral collection. Which of the following terms can both be used to describe luster?

Group of answer choices

hard and coarse

metallic and soft

grainy and rough

glassy and metallic

Shane uses a hand lens to examine a piece of granite rock. He observes that the granite is made up of very large crystals.

Group of answer choices

minerals

fossils

soils

shells

Aresearch study is studying the effects of a new drug for osteoporosis alzheimer's disease (ad) for women above the age of 65 years. a group of individuals with osteoporosis is randomized into two groups. one group is treated conventionally, and the second group is treated with the new medication. assessments are made at 3, 6, 12, 36, and 48 months. the conventionally treated group is assessed for ad using a serum blood test, and the treatment group is assessed for ad using a pet radiotracer that binds to beta-amyloid plaques. in comparing these 2 trial arms, the authors of the study may encounter which type of bias? a. selection bias on the risk of developing b. measurement bias c. confounding bias d. recall bias e. lead-time bias