What part moves the body tube and objectives up and down

Pre-assessment: choose the letter of the correct answer35%250-q chocolate mousse which ischocolate, 30% cream, 20% milk. 10%a to prepare amuch cream are you going to use? m, 20% milk 10% sugar, and 5%sugarbutter, howa 75 g creamc.73 g creamb.60 g cream0.62 g cream2. cheska measured the mass of 10 pieces of each ofe mass of 10 pieces of each of the following materials: marble, pebble, and ballpen cap. what will beballpen cap. what will be her findings based on the datashe obtained? table 1. data on massmaterials(10 pieces)marblepebbleballpen capmass(9)503520s have diffes differa. different materials have different masses.b. materials of different kinds differ in amount, color, and texture.c. the same number of materials has different colors and appearance.d. the same number of materials of different kinds has different masses.different3. the following are representative particles of matter. which among themrepresents a covalent compound? a. atomc. moleculeb. iond. particle unit4. a bag of npk fertilizer marked 16-4-8 contains 16% nitrogen, 4%phosphorous and 8% potassium, the other 72% is usually inert filler materialsuch as clay pellets or granular limestone. what is the mass of nitrogenpresent in the 500g pack of npk fertilizer? a. 80gc. 209b. 40gd. 1095. how many particles are equal to 1 mole? a. 6.02 x 1022 particlesc. 6.02 x 1024 particlesb. 6.02 x 10- particlesd. 6.02 x 10"particles6. how can the knowledge about mole be useful for environmentalists? a. mole concept can be used in environmental monitoring.b. it gives information on the most dangerous pollutant in the atmosphere.c. it gives a feedback on the kinds of pollutants present in the atmosphered. mole concept can be used in quantifying the amount of pollutant-particles released in the atmosphere.146​

Give a brief description about 3d printing,then in your own idea,how is the 3d printing help in sustaining the development of the humanity?

Mag bigay ng halimbawa ng concave lens​